The Hogwarts Express

In the weeks that passed, Cassie fought the insomnia that relentlessly plagued her. If her consciousness had been afflicted with negative thoughts before, it was bombarded now. She and Severus had endured countless conversations about the fate that Sombria's son had met, and none of his meticulously uttered words could comfort her. His patience had worn out eventually, and he had all but tried to bully her into taking a sleeping draught. After numerous refusals to help herself with his carefully brewed potions, something nearly miraculous had happened. Severus had appealed to Harry. With the Head of Slytherin's coaching, the boy was finally able to convince her to drink the elixir by expressing genuine concern while looking at her with large, innocent green eyes.

Their collaboration both astounded and amused her. It seemed in the recent days the two wizards had bonded over Cassie's wellbeing, to the point that she felt comfortable leaving them alone in a room together. Twice now she had stumbled upon them actually having cordial conversations. At one point when she had come back from a run, she had to search the small homestead, as they weren't inside the cottage. She had found them out in the garden playing wizard's chess, seated in wicker chairs that Severus had conjured. She wanted to tell them how happy she was with their growing friendliness with each other, but she knew better. Saying something would only make one, if not both of them regress to their usual stubborn states.

Two weeks before term started, the three of them ventured to Professor Kettleburn's home outside of Bradninch. Harry had been reluctant to visit the transfigured basilisk, although Cassie could hardly blame him. After reassurance that the serpent would remain in its much smaller and less lethal form while they were there, he had agreed to come with. It was a relief for Cassie, as she had wanted Severus to be there in case the spells keeping the animal weren't holding up, but they wouldn't dare leave Harry alone while they were away.

The retired professor led them through his small home to the backyard, which had been enchanted to accommodate the creatures he was looking after in his free time. Seemingly thrilled to have some familiar company, he chatted about his recently-obtained flock of diricawls while a giant storm petrel squawked at them from a two stories-high perch.

"How has the basilisk been behaving, Silvanus?" Severus asked as they descended further into heavier vegetation. There were so many trees now that it reminded Cassie of being back in the Amazon.

"Boros has been perfectly splendid to care for," Kettleburn replied. "No problems whatsoever."

"'Boros'?" Cassie asked.

"You know, after the ouroboros. I started calling him that and he responds to it. Hope you don't mind," the wizard said.

"Not at all," she said, catching Severus' eye and smirking.

They came across the serpent coiled up on a branch. Kettleburn called up to him, but the snake had already started moving once he had noticed the visitors.

"Mistress," the reptile hissed as it slithered down the trunk of the tree. Cassie instinctively reached out, allowing the serpent to move across her arms and onto her shoulders. "Have you brought food?" Its question was eager, and Harry's worried expression broke into a smile.

"Your caretaker warned me that you're a bit of a glutton," Cassie responded lightly, catching Severus' eye and nodding to her pocket, as her limbs were currently occupied with holding the heavy animal. He reached in her robes and pulled out a large dead rabbit, and Boros eyed it hopefully. "Go ahead," she said. Severus flinched as the snake struck and latched on to the meal that was still in his hand. It slowly circled down Cassie's body and made its way back up the tree with its prize.

"The spell seems to be holding up well?" Severus asked then, his eyes tearing away from the animal as it unhinged its jaw to devour the rabbit.

"Hasn't seemed to be any trouble. But you said Minerva performed it?" Kettleburn asked, watching Boros in delight. Severus nodded. "Then we shouldn't have any problems, I expect."

"So it could turn back to...normal...at any time?" Harry asked.

"Theoretically," Severus told him. "But we used complex magic to contain it in this form."

"And I gave him specific instructions not to intentionally harm anyone," Cassie reassured him. She could tell that he was still bothered by the situation.

"But the eyes," Harry continued quietly. "That it can't help, can it?"

"If everything goes as we intended, it will have a covering over its eyes when it reverts back to its true form. And hopefully, that will only be when we do it on purpose," she said.

"So you just expect that it will listen to you?" the young Gryffindor asked in disbelief.

Cassie watched him carefully, unease apparent in his features. She gave him a small smile. "You can talk to him, Harry. Do you want to try?"

After a moment's hesitation, Harry nodded. "Hello," he hissed. Now, Severus was the one to look uneasy, his lips pressed together in a thin line as he watched the interaction. No doubt, previous conversations of how The Boy Who Lived obtained this ability was going through his mind.

The serpent's mouth was still full of its meal, but its gaze went to Harry immediately. "This is Harry. He speaks our language," Cassie explained. Boros continued to watch Harry as it swallowed the animal. Harry still seemed tense as the human conversation turned to Hagrid's new appointment as professor. Finally, when the rabbit had disappeared down the snake's throat, Boros responded.

"Hello, Harry. You are friend of Mistress?"

Harry looked to Cassie, and she nodded for him to respond. "Yes."

"Then Harry and Boros are friends, too."

By the time they left Kettleburn's enchanted habitat, Harry was in much better spirits, the relief obvious in his stance. But the curiosity in him hadn't seemed to be quelled yet. "Why are you keeping him?" he asked as the three of them walked down Kettleburn's driveway.

Cassie weighed her words carefully before responding. "He might come in useful someday." It was a vague answer, one that would be unlikely to satisfy him. But she could hardly tell the thirteen-year-old that another war was imminent.

Harry didn't press the matter, likely knowing that she wasn't going to explain further. But Cassie could see the wheels turning in his head, and she wondered yet again if the adults in his life were doing him a disservice by not disclosing the entire truth. It was a concern she had brought up to Severus many times recently, and he only had one answer for her: Dumbledore didn't want Harry to know that Lord Voldemort's return was inevitable.

Remus Lupin.

That name, which had been so carefully written in a letter from Dumbledore, had nearly ruined what little peace was in the house. The Headmaster had at least thought to let Severus know ahead of time that the wizard would be taking the Defense Against the Dark Arts position that term. Cassie couldn't decide whether it would have been better for Severus to find out when he had arrived at the castle.

"What is that old man thinking?" Severus seethed as he tossed the letter onto the table. Harry was up in his room and hopefully out of earshot.

"Do we ever know what he's thinking?"Cassie quipped as she pulled the parchment to her. Dumbledore's words were polite and straightforward, telling Severus that the decision had been made because Lupin knew Sirius best out of anyone and that having him at Hogwarts would help keep the students safe. Cassie grew puzzled at Severus' reaction after reading it, as the Headmaster's logic was sound. "Well, he actually has a valid point, Sev."

It was the wrong thing to say. The Head of Slytherin rounded on her, thin lips pulled into a sneer. "Must I remind you of the things I told you at Christmas? What Potter and his little friends were like?"

It took her a moment to grasp what he was getting at. "Oh, but Severus, that was a long time ago - "

"So we might as well forget it even happened!" he snapped. "Not to mention that a werewolf will be inside the castle!" He had told her of Lupin's affliction many months ago when recalling his time at Hogwarts. Cassie sighed.

"I'm sorry. That's not what I meant. But what Dumbledore said makes sense. If anyone knows what Black might be up to, it would be his former best friend, right?"

"You don't yet realize the implications," he growled, taking a seat across from her at the table. "No one knew that Black was capable of what he did, his friends included."

Cassie thought her lover's words over carefully. "So Lupin doesn't know him better than anyone else would," she ventured, hoping she was correct in what he was trying to get at.

"Or he knew and somehow got off scot-free. In which case, having him at Hogwarts is the worst possible decision the Headmaster has made yet!" A frustrated scoff left his throat, and then he pointed down to the letter again. "Did you get to the end?"

She started to read it again, as she hadn't quite finished it. Then she saw what was contributing to Severus' anguish. Lupin had taken the job under the promise that Wolfsbane Potion would be provided to him throughout the school year. "Oh."

"As if I don't have enough on my plate!"

"I'll help you," Cassie said quickly.

"The potion is incredibly complex," he said icily. "It will be done by me and me alone."

"Severus," she said carefully, "don't do this. Please."

He glared at her. "Do what?"

"Revert back to this solitary mindset. You might not want me touching the potion as you brew it, but I will still be there for you."

Her words seemed to pierce through his iron wall, as his expression softened the tiniest bit. "You will be just as busy as I am patrolling the castle on top of your other duties."

"And now it seems I'll be keeping an eye on Lupin as well," she said. "But it doesn't make a difference. I'll always have time for you."

"Stop with the sentiments, Cassie. This is serious."

"So am I." She stood and rounded the table to him, placing her arms around his neck. "You've been here for me through this entire holiday as I've dealt with seeing my mother. And finding out what happened to that little boy...let me do the same for you." Lowering her head to his neck, she placed a gentle kiss behind his ear.

"Can't a man be left alone for once?" he muttered, and she smiled against his skin.

"That's not what you want," she countered softly.

"And you know what I want?" Her lips found his earlobe and she sucked lightly, earning a satisfied hum from the Potions Master's throat.

Footsteps coming down the stairs reached their ears, bringing their intimate moment to a screeching halt. Cassie had removed her arms from Severus' frame before Harry entered the kitchen, but the blush on her face gave away something. Harry couldn't completely hide the revulsion on his face.

"Good morning," Cassie said, clearing her throat.

"Morning, Potter," Severus echoed, hastily tucking the letter into his pocket.

"Morning," Harry said, eyeing his professor's movements warily.

"I'll get breakfast started," Cassie said, pulling ingredients from the cupboard.

"That had Professor Dumbledore's seal on it," Harry said. Cassie could almost feel the tension start to form in the room as Severus' annoyance sprang forth.

"Indeed," the older wizard quipped. Silence filled the air for a few moments.

"Is it about Black?" Harry asked.

"No."

"What did it say, then?"

"Nothing that is any concern to you," Severus snapped. Cassie huffed as she threw food into a pan, unable to hide her disappointment at Severus' harsh response. She knew from the moment he found out about Lupin's appointment that his patience would be nonexistent.

"It's just about the new Defense Against the Dark Arts professor," Cassie said. "He sends those letters to all the staff." She wanted to explain to Harry who exactly this new professor was. But if Dumbledore had wanted Harry to know that he had been friends with his parents, he would have sent a letter to him as well.

There was still obvious strain while the three of them ate. Little was said until plates were being cleared, and then Harry received an owl. It had brought a letter from Hermione requesting that he spend the night at Diagon Alley the night before leaving for Hogwarts. The Weasleys would be there as well, and it would give them all a chance to catch up before the school year started.

"Would that be alright?" Harry asked hopefully, looking from Severus to Cassie.

She looked over to the Potions Master. His mood seemed just as sour as it had before. "I don't see why not. Of course, I'll have to spend the night there, too," she said.

Harry nodded, then glanced over at Severus. "No worries, Potter. I'll be going to Hogwarts a few days early to prepare for term. I won't be joining your little party," he said irritably. Harry opened his mouth, perhaps to protest that he hadn't been thinking anything of the sort, but the raven-haired wizard left the room abruptly.

"It's not you," Cassie said quickly, as Harry had been staring after him in surprise. "He's just got a lot on his mind."

"Sure," Harry said. But like so many times that summer, Cassie was under the distinct impression that Harry didn't quite believe her.

The eve of Severus' departure was soon upon them. Cassie was feeling a bit soppy, knowing that they would not be spending time together in this little cottage perhaps until the next summer holiday, but it was nothing compared to last year when she left for South America. When she reminded herself that she would get to see him every night at Hogwarts, all feelings of melancholy disappeared.

"What are you thinking, my love?" Cassie asked as she laid in bed with him that night, her arm and leg lazily draped over his body. Neither one of them was clothed, and no doubt their recent activities had worn them out. But both of them seemed to be thinking too much to fall asleep.

"I am wondering to what lengths Black might go to," he murmured lowly. "Just make sure you keep a close eye on Potter. Merlin knows he seeks out mischief."

"Noted," she said, placing a light kiss on his collarbone. It was silent for a few minutes before she spoke again. "I don't remember ever seeing Black at my father's meetings. Not once."

"Of course you wouldn't remember. He was a spy."

"It just seems odd, doesn't it? Everyone that says they knew him didn't expect any of it out of him, from what I've heard."

"Then he wouldn't have made a very effective spy, would he?"

"Knowing him from school, would you have ever expected him to do what he did?"

"It doesn't matter," Severus spat.

"No, maybe it doesn't." She left the topic alone then. Her mind went from thoughts of Sirius Black's motives, to what Severus had endured at his and his friends' hands while they were at school together. At once she was feeling rather cross with the new professor they were being forced to work with.

Meeting up with her pseudo-family at The Leaky Cauldron was perhaps the best therapy she didn't know she needed. As Harry exchanged stories with Ron and Hermione, Cassie sat between Arthur and Molly. She couldn't count the number of hugs the Weasley matriarch bestowed upon her, and Arthur was as animated as ever as he recounted their adventures in Egypt. The mood only dampened when Fred and George distracted most of the kids while taunting Percy, and Arthur murmured in her ear that he had heard about her trip to Azkaban with Fudge.

"Kingsley told me everything," he said, and Cassie grimaced. "I'm so sorry it turned out that way. Fudge should have given you some warning when you were nearing Lestrange's cell."

"He had a job to do. Babying me should have been the last thing on his mind," she replied quietly.

"You were doing him a favor," Molly hissed in protest. "That's the least he could have done for you. And the reaction of those prisoners - I hope you don't think about it too much, dear."

"Of course not," Cassie said quickly. She watched Percy, red-faced, as he tore after the twins for taunting him about Penelope Clearwater. He nearly tripped over Hermione's new orange cat, who was spitting angrily at Ron.

"You don't have to act stoic with us," Arthur reminded her gently.

"I know," she said, tearing her eyes away from the chaotic scene so she could look the kind wizard in the eyes. "It's just that I don't have the energy to talk about it again. At least not right now."

Arthur and Molly exchanged a glance, something that couldn't be hidden since she was right between them. "If you say so, dear girl," Molly said, wrapping her arms around her again. "Just know that you can always come to us. With anything." As always, Cassie believed her.

The next morning, Cassie found herself stuffed between two Weasleys yet again, although this time it was between Fred and George. The Ministry had insisted that the large family, Harry, Hermione, and Cassie take a small fleet of cars to King's Cross as a favor to Arthur. Cassie didn't believe for one second that the kids didn't realize it was to keep Harry safe from Sirius Black. Hermione had asked her why she and Harry hadn't just Apparated to Hogsmeade; Cassie admitted that she had considered it, but realized that Black might attack the train either way. So she would be among the Hogwarts student body, hoping that if something happened, she would be able to keep them safe.

If being discreet had been on the agenda, they had sorely failed on the matter. Between the gaggle of red-heads and The Boy Who Lived, there was no way Cassie could hide the fact that she would be riding the Hogwarts Express unless she used an illusionment charm. She briefly considered casting one after the tenth set of parents thanked her for her services in South America and being willing to keep Harry Potter safe, but she realized that if Black was somehow at the platform and watching, perhaps her presence would deter him from trying to attack. So she endured the staring and the gasping, pushing through the crowd to make sure all of the students with her got to the train safely.

After instructing Harry and the others to stay with Arthur and Molly outside, she left her group to enter the train alone. She wanted to do a once-over before Harry boarded, and started by going to speak with the conductor. She explained who she was and why she was there, and he shrugged.

"Already been a professor looking over all the compartments," he said. "Seems a waste of time for you to do it, too."

"I'm sorry," Cassie said, instantly feeling wary, "But who already did a search?"

"A new guy. Lupin, I think."

"I'll do my own search, thanks," she said. Time would tell if she could trust the DADA professor, and she wasn't about to give him her blind faith now.

Nothing looked awry. Some students were already settled into their compartments, a few of the older ones looking surprised to see her suddenly appear. She offered quick explanations and continued on. She found the disheveled form of Remus Lupin toward the back of the train, and he looked as if he had already settled in for the journey.

"Hello," she said, making a point to look him square in the eye so he would take her seriously. "Are you Professor Lupin?"

"I am," he said, giving her a weary smile.

"And you've already done a once-over of the entire train?" she asked bluntly.

"I have. Everything seems in order, from what I could see."

Cassie nodded. "I'm - "

"Cassiopeia Black, I know," he said, then looked sheepish after cutting her off. "Sorry. It's just that your face has been plastered all over the Prophet." To prove his point, he flipped the paper in his hands over to show her that she was on the front page next to a picture of Dumbledore. Cassie grimaced.

"Something good, I hope."

"Just that the Headmaster has given you a position at Hogwarts."

"Well, the parents will either be elated or terrified, as usual," she said, a humorless laugh leaving her. She shook her head then, wondering how she had been pulled into such a polite conversation with his man within seconds when Severus had painted such a negative view of him. "I'm planning on patrolling the train throughout the ride. If something seems amiss, come find me."

She did just that. During her first complete patrol of the Hogwarts Express, she wasn't sure how to feel when she saw that Harry, Ron, and Hermione had somehow ended up in Lupin's compartment. She reminded them to find her if anything seemed wrong, and Ron rolled his eyes at her. At least the professor seemed harmless, curled up in a ball as he slept, although she wasn't sure this wasn't a ruse so the kids would let their guard down. She made it a point to check on them more often.

As they neared Hogsmeade, her attention was pulled away when a fourth-year Hufflepuff approached her, timidly telling her that some Slytherins were tormenting a first-year girl. Cassie wasn't all that surprised to find that the culprits were her cousin and his two cronies.

They were in the girl's compartment, and she had pushed herself into the corner, her legs pulled up to her chest. Two other young students, who by the looks of it were also first-years, were behind the trio of bullies looking helpless. Cassie heard the word 'mudblood' leave Draco's mouth, and she didn't need to hear any more to know that there needed to be a swift intervention.

"Malfoy," she seethed, and the blond Slytherin whipped around. His much-bigger friends did the same, looking at her with their mouths wide open. "Crabbe, Goyle. Out of this compartment. Now." They obeyed, Draco looking very much like a kid caught with his hand in the cookie jar until other Slytherins arrived to witness the exchange. As soon as the Parkinson girl and two others were nearby, his usual smug expression returned.

"Cousin," Draco drawled, casually folding his arms across his chest as more students stuck their heads into the corridor. "Good to see you. It's been too long."

"Enough with the arrogant attitude," Cassie said evenly. "If I hear you've bullied one more student on this train - "

"You'll what?" Draco interjected coolly. "Hex me? You're not a student anymore. You'll be sacked if you do anything of the sort."

"I can't hex you," Cassie said, sneering at him. "But I can sure as hell give you a week's worth of detention before we even reach the damn school."

"You can't - " Parkinson tried to interrupt.

"I can," Cassie said firmly. "And if I hear one more word from you, you'll be joining them!" She turned back to Draco. "Let's go over the other things I can do, shall we? I can take your house points, suspend you from the Quidditch team - "

"Professor Snape won't let you!" Crabbe said stupidly.

"Professor Snape can't say a word against my punishments," Cassie replied, "as I have the same right to hand them out as he does."

Students immediately started to disperse at this statement. Apparently, none of them wanted to get caught up in whatever discipline she would be handing out to the Slytherin trio. "Fine," Draco snapped. "I'll be a good little boy the rest of the train ride, I swear - "

He stopped talking when the train came to a screeching halt and all of the lights went out. Cassie's heart started to thud in her chest. "In your compartment now!" she said, and the third-years obeyed without question. After lighting her wand and making sure there were no other students out in the aisle, she started to make her way to Harry's compartment. If this was Black, what kind of power did he possess to stop the train so suddenly? She had to get there before he did -

And then a familiar feeling swept over her, one that she had felt only earlier that summer. The air around her grew cold, and any inkling of joy was sucked out of her. Within moments she wondered how long she could do this, how long she could stay sane, and she knew that Sirius Black was not on the train. It was the dementors.

She was only feet from Harry's compartment when one was suddenly in front of her, blocking her view. Trying to see around it, she craned her neck, only to witness another dementor enter the compartment. Her attention snapped back to the dark creature in front of her.

"Black is not on this train," she said, her voice coming out in a wheeze as she tried to sound authoritative. "Leave!"

She heard whimpers and small cries of fear, and she hoped that whatever was going on that Lupin was handling it. It wouldn't be long before this feeling overtook her, made her lose herself, and even as those thoughts crossed her mind a skeletal hand reached out from the black cloak and to her neck. All at once, nightmarish memories flooded her consciousness. She saw her mother in Azkaban, pleading for help; Sombria killing Alex, and then Sombria's dead body at her feet; twisted, mangled bodies of those she had been too late to help while in South America, and similarly tortured innocents from her childhood, ones that her father had just mutilated. She was sucking in the chilled air, trying to ground herself when that hand closed around her neck, the other pulling back the dark hood.

Cassie couldn't waste time trying to tell the dementor to leave the train. She could see it was tempted to suck even more from her, and she couldn't know if it would try to do the same to the students. Her hand, which was still miraculously closed around her wand, rose to the creature's head, or at least where one should have been. All at once, she did what she had practiced so many times and thought of the very thing that brought her complete joy and elation: Severus Snape.

Her Patronus, in the form of a runespoor, erupted from her wand with so much force that she stumbled backward. She hadn't even known that Percy was right behind her until he caught her and kept her upright. The dementor turned to flee at once, and another Patronus chased the second from Harry's compartment at nearly the same time.

She was still struggling to catch her breath when the lights flickered back on. "Thanks, Percy!" She turned to give the Head Boy a quick hug, and then hurried to see if Harry and his friends were alright. Ron, Hermione, Ginny, and Neville seemed shaken but fine. But she couldn't find her voice when she saw that Harry was unconscious, and just as she rushed to him, he opened his eyes. Thankfully, Remus Lupin was fully prepared with a large block of chocolate, something that she couldn't help but be grateful for as he handed it to Harry.