You are my secret Psychiatrist.

Do-hyun struggles in Ri-jin's grip. He forcefully frees himself, which surprises Ri-jin and Chief Ahn. They simultaneously exclaim, "Shin Se-gi?!"

"I'm Cha Do-hyun!" he yells at them. They're not used to seeing gentle Do-hyun mad. As if he isn't there, Ri-jin and Chief Ahn discuss him, worried his fit of temper might provoke a switch. He insists that he's not annoyed, but when Ri-jin encourages him to express his feelings, he bellows at her. Ri-jin and Chief Ahn reel and ask again, "Shin Se-gi?!" Hahaha.

Do-hyun drops a ton of reading in front of Ri-jin, and enjoys her dismay. They include his patient histories from Dr. Seok, detailed profiles on each alter, and his personal diaries from the last eleven years.

Ri-jin asks where she'll be living — is it somewhere nearby? She hasn't looked at the contract yet, so they explain that since she needs to keep an eye on Do-hyun 24/7, she has to live with him. She has a little meltdown.

Composed again, she asks what they'll do when he's at the office. Chief Ahn cryptically mentions a disguise while Do-hyun is a picture of innocence. Haha, he's relishing this so much. It must be the first fun he's had in years.

Outside, the chief asks Do-hyun what'll happen if she turns it down. He repeats Do-hyun's earlier words about not letting her get close to him, and notes how Do-hyun contains his own emotions so strongly — but for the first time in eleven years, Chief Ahn saw him get annoyed because someone got past his walls. (Do-hyun: "I didn't get annoyed!") His parting advice to Do-hyun is, "Don't lose her."

Do-hyun catches Ri-jin trying to sneak away, but he pulls her back by the collar. Ri-jin: "Shin Se-gi?!"

"I'm Cha Do-hyun," he says, and marches her back in.

She complains about the "slave contract" (apparently the disguise is to be his "secretary") and he says it's her fault for not reading it first. He tells her to check her account, and the amount deposited makes her eyes pop.

If she takes the secretary-guise, he offers to double it. She laughs in his face and even refuses triple (though it clearly pains her) and tries to run. He holds her back again, and reminds her that they agreed that she can't turn back, and he can't send her away.

Maybe she's looking for a way to stay now, because she's grinning madly at him the whole time, no longer refusing. She feigns a leg cramp as an excuse, and he goes along with it. He kneels at her feet to massage it out, and they share a sweet moment.

Chief Ahn brings Grandma Seo up to speed on Do-hyun's trustworthy new doctor. She orders him to investigate her background anyway. Before leaving, he asks if she actually knows what ails Do-hyun. Instead of answering, she tells him his discretion was a big part of why she employed him and saw to his education. Hm, so she owns him? She warns him not to hold hands with the other side, and to stay with Do-hyun.

Ki-joon's interview with Dr. Seok proved unfruitful. He had tried to probe for information on Do-hyun's condition, having noted his strange behavior. Ki-joon's guess is drugs or alcohol, and he pleads with worry about his cousin. Dr. Seok merely explains Do-hyun away as one of his many students — a scenario Ki-joon doesn't buy. He thinks Do-hyun is trying to outmaneuver him for control of the company.

He's surprised to receive a call from Do-hyun's blind date, Ji-sun, who asks after his and Chae-yeon's relationship.

He looks for Chae-yeon, and orders her to apologize to Ji-sun, so as to quell the rumors going around about her. He censures her for making a scene at Do-hyun's blind date, despite her engagement to him. The juicy story causes people to question her motives, especially since Do-hyun emerged as the prime successor to the company.

Livid, she says she did it for Ji-sun's sake, because she couldn't stand Do-hyun coveting her friend's stocks. Ki-joon wants to cut off the rumors by getting engaged already, but his mode of proposal upsets her. He shouts that she's the one showing him up and making a mess of his engagement. Oh you two are as bad as each other.

Chae-yeon flips out and tells him she's not getting engaged until after the shareholder meeting.

Meanwhile, Do-hyun tutors Ri-jin on the alters' personalities, and she's particularly interested in the two she hasn't met, Nana and Yo-na. He also familiarizes her with the people he needs to hide his illness from at all costs, including Grandma and Ki-joon's dad.

He authorizes her to use any means necessary to keep the altars in line. She meets the instruction with a cute salute, distracting him into a warm smile. It brings Chief Ahn's question back to his mind, whether he's confident about keeping her at a measured distance.

The next slide is Ki-joon and Chae-yeon, whom she teases him about — she's so pretty, he must have like-liked her. The doorbell saves him from responding.

It's Chae-yeon. Upset, she beats on him for making her into the "protagonist of a makjang drama" — isn't she his first love? Who is really in his heart — is it that woman, Oh Ri-jin? Inside, Ri-jin has her ear to the door and listens in shock.

In answer, he calls Ri-jin to come out. Ooo. Reluctantly, she complies, and he makes a show for Chae-yeon…who answers him with a slap. Ri-jin tries to explain, but Do-hyun wordlessly holds her back while the other woman leaves.

Examining his face, Ri-jin offers to be his drinking buddy if he's not okay. He just tells her their lessons are over for the day.

At the Oh house, Mom and Dad mope and pick at their breakfast, worrying about Ri-jin. Ri-on, on the other hand, is all appetite and scolds his parents for their over-concern — that's why Ri jin is all messed up inside, he says, taking on everyone else's pain as well as her own. He leaves the table.

Instead of working, Ri-on looks through old photos on his computer and each photo brings up a memory. A childhood snap takes us to little Ri-jin and Ri-on. Mom urges them to smile — they're oppa and dongsaeng now. Awww Mom, I love you.

Dad joins their hands and Ri-jin smiles shyly at her new brother. But he throws her to the ground with a glower, so she launches herself at him in a retaliatory headbutt, as the parents try to break it up.

The memory makes Ri-on smile. Next is high school, where their fighting relationship continues, although it's now full of affection (sort of), as Ri-jin grabs him by the throat for stealing her homework. The arrival of her crush saves him, as she goes all googly-eyed. But later, Ri-on catches the guy getting kissy with another girl, and protects his sister from seeing it.

Mom bursts into his room and he slams the laptop shut. She confronts him about his nekky posters and grabs the computer out of his hands. She's subdued when she sees what he's really been looking at. He totally plays it up and runs off wailing like a toddler. Lol.

Dad starts to ask Mom something to do with the twins, mumbling something cryptic about rumors abounding about "that family," but she shuts him up.

Chief Ahn updates Do-hyun about the Omega fan club reading, which is today. Ri-jin pops in to make coffee, and her ears prick up when she hears her brother's name. Chief Ahn hasn't been able to procure a photo of the elusive author, but shares the rumors he heard (from Ri-on, ha) of Omega's "Won Bin-level looks." Ri-jin sprays her coffee all over Do-hyun in incredulity. HAHAHA, say it, don't spray it!

Do-hyun maintains his careful indifference to her and suggests to Chief Ahn that they head out for the event. But Chief Ahn has an unavoidable appointment and excuses himself, so both men turn to Ri-jin, who wails at her bad luck. Lol, Chief Ahn just appointed himself Chief Wingman.

Chief Ahn recites Rule 2 of the contract that stipulates that she has to be by Do-hyun's side 24/7. She counters with Rule 4: Except while they are secretary and VP, she and Do-hyun have equal standing. So her condition for going along today is that she gets an hour of counseling with him each day. Not for treatment, she tells him: "Let's be friends." She badgers him until he finally agrees.

Chief Ahn's appointment is with Do-hyun's mom. She doesn't mince her words and asks him whose side he's on — is he Grandma's spy, or is he faithful to Do-hyun? She warns him that he'd better not backstab Do-hyun.

Ri-on's mom watches him from afar with concern. He wishes his sister had stayed after all, chaebol doctor or not. His editor calls to tell him his fan club reading is on. But he has a bad feeling about it and warns Ri-on not to go, since it might risk his cover. ID Entertainment is going all-out to try and secure the film rights for his books, he adds. Ri-on casually confirms that it's a Seungjin subsidiary.

The reading is atmospheric and lively. Among the audience, Do-hyun is on the edge of his seat, caught up in the mood. Aww, that unguarded laugh. It concludes, and Do-hyun turns to Ri-jin to share his excitement…HAHA WHAT. He wonders if being all covered up isn't more noticeable, and she warily unwraps — just as Ri-on bounds in. She panics, almost spilling his secret identity to Do-hyun.

She makes a save by saying her brother is Omega's fan — but she can't be seen by him because he thinks she's in the U.S. Do-hyun catches her panic now, too, and helps bundle her out.

Ri-on spots Do-hyun and calls out, "Perry!" The two escapees freeze, and Do-hyun tells her to run while Ri-on pounces on him.

Do-hyun distracts him from Ri-jin by grabbing his ears in greeting. HAHA. Ri-on squirms in his clutches and points at all the people. Once he's sure Ri-jin got out safely, Do-hyun lets his ears go with an apologetic laugh.

Away from the hubbub, they have a quiet conversation. Do-hyun tells Ri-on that he came looking for Omega, and is surprised to find him a fan. Ri-on mentions two books in particular. One is the "Switched-twin Murder Case," and the other is "The Child in the Basement." Those happen to be the only ones Do-hyun hasn't read.

Ri-on outlines the plot of the latter: A boy and a girl became like siblings after an accident. It then sounds like the story Ri-jin told Do-hyun about herself — a girl who is afraid of basements, whose parents send her there on chores to cure her of her fear.

Ri-on adds more, and we're given a flashback with little Ri-jin and Ri-on. Every time she had to go down there, she took him, too — and he would go, despite his own fear. But eventually, he began to question why he was afraid. Although he discovered the reason, the girl never remembered. The boy, Ri-on says, made it his mission to find her lost memories.

Do-hyun becomes increasingly agitated by the story, and relives his fragmented memories of his own nightmare-basement. He nearly collapses, and Ri-on runs to get him water.

Sweat beads on his face, and Do-hyun struggles to stay conscious. Then, a hand takes his — it's Ri-jin.

Ri-on returns to an empty room, and he goes out just in time to see her get Do-hyun into his car. He frowns, "Ri-jin?" He runs after the departing car, but it's already out of his reach.

In the car, she tells Do-hyun to hang in there. He clutches his head, and she keeps up a stream of reassurance. She's worried when he knocks out, and keeps calling his name.

His head snaps up, and…it ain't Do-hyun anymore. With a head-toss and a ton of attitude, this has got to be Yo-sub's twin, Yo-na. S/he orders Ri-jin to stop the car, and complains, "Girl, you're so noisy! Stop talking! Close your mouth!" The bossy alpha-teen girl-talk coming out of Ji Sung's mouth is…omg I'm dying — I don't know what's funnier, Yo-na's scolding or Ri-jin's startled compliance.

Ri-jin recalls what she knows about Yo-na. Dr. Seok nicknamed her the "manager of suffering." When Do-hyun is extremely distressed but needs to keep his head down, she absorbs it. Do-hyun considers her the most dangerous — a boy-crazy, idol-chasing sasaeng fan. It's hilarious how outraged he is by her behavior.

Yo-na filches Ri-jin's hair clip, and we see her as she sees herself, in pink lipstick and a pink school uniform blazer. She agonizes over her ajusshi face. Ri-jin is speechless.

Suddenly spotting an idol-oppa, she's out of the car in a flash. Oh man, that flaily, girly running. HAHA. Ri-jin gives chase.

There's a fanmeet for idol group "Rocking", and they explain how their edgier music attracts more male fans — and look, here's one of them now! Yo-na pushes her way to the front, squealing for her oppas…except to the rest of the world, she still looks like Do-hyun. She nearly dies when she's invited on to the stage.

Her moment is interrupted by Ri-jin, who gets her with a missile to the head. Oh no, now it's on: It's a catfight, with hair-pulling and screaming. A crowd surrounds them, filming and snapping photos (not good!), shocked that a guy is beating on a girl.

Yo-na gets out of Ri-jin's grip and runs for it — thwack into a post.

On a subway station bench, Do-hyun comes to. With tissue-plugs in their noses, he struggles with the hair clip while she explains the situation. The car got towed, it was cold, she couldn't take him to hospital…so here they are. He apologizes, the weight of the world back on his shoulders.

Ri-jin asks what his extreme suffering was that brought Yo-na out. Was it something Ri-on said? Or Chae-yeon? But then she cancels her questions, since they're not friends, and he doesn't answer them anyway — she'll settle for being rich. Or asking Se-gi, because at least he talks to her, "Although the problem is that he says what he wants."

She's ready to go, but he catches her arm. Sitting back down, he hesitantly asks if she wants to go for a drink, and reminds her of her offer to be his drinking friend. She replies that he doesn't like drinking or friends. Still faltering, he says they could start those counseling sessions.

Ri-jin is impressed by how much alcohol Do-hyun can put away for someone who doesn't drink, but figures that Se-gi and Perry must have done his body's share. He tells her they're in session and she can ask him questions — but first he apologizes for the night before. That friend, Chae-yeon, was his cousin's fiancée, and he confirms she was his first love. But when he found out she was being nice to him in order to get closer to Ki-joon, he was hurt, and moved on.

Ri-jin observes that he didn't look like he was over it. But he explains that he's never taken anyone into his heart since his diagnosis, afraid of putting them in danger. But when he sees Chae-yeon, he remembers the time when he was able to love someone freely — maybe it's really the freedom to love that he loves. That actually explains a lot. He asks if that answers her question. Ri-jin: "I…didn't ask." HA. Way to undercut the deep moment, lol.

Do-hyun marks that they're halfway through their session, but Ri-jin objects — that was just a conversation, not a consultation. If he wants counseling, they can start now.

He reaches for her wrist and, tapping her watch, tells her to take note. "January 29, 2015," he notes as he waits for it to strike the hour exactly. "10 o'clock. First consultation… commence."

The echo of Se-gi is not lost on Ri-jin. "Shin Se-gi?" she asks him. His exasperation is never going to get old: "I'm Cha Do-hyun!" He wonders if she's secretly hoping for Se-gi to appear, and she teases him for being all jealous of himself. Flustered, he denies it.

They walk home, and Do-hyun asks her why she stayed by his side. "Was it a pity? Or so you could meet Se-gi through me?" She thinks about it, and gives two reasons. Firstly, Yo-sub. His "Kill me" message seemed to her like a call for help. Secondly, Do-hyun himself. When he told her he wouldn't return the ball that went over his castle walls, it made her realize how much he needed her.

He asks if she isn't afraid of all the people living inside him. She's not — she wants to be close with all of them, and she has things to say to them. "From now on, instead of 'kill me,' ask, 'heal me,'" she tells him.

Being healed doesn't mean they'll die, she says. Rather, they'll carry on living in him — she points to his heart. But instead of being scattered fragments, they'll be a connected puzzle, fitting together to make a wonderful picture. "With the name of Cha Do-hyun, you guys will become an even more wonderful person," she finishes.

He stares at her, heart in his eyes. Clasping the hand she's pointing at him, he leans in and kisses her. When he pulls back, she searches his eyes. He smiles at her and says unasked, "I'm Cha Do-hyun."

He draws her close again, this time slow and deliberate. She closes her eyes — and Se-gi's threats about messing with his woman rise in Do-hyun's mind. He pauses, but looking into Ri-jin's eyes, he kisses her again anyway.