Chapter 1: Floating corpse under rusty umbrella

I. Found corpse in the morning

In the morning on Seventh Avenue, the mist covered the street like gray gauze, and the cold wind with ice chips stung the skin. Niu Aihua rode a police motorcycle, the engine roared on the icy road, shaking her hands numb. When she turned the corner, the tires slipped on the thin ice, and the brake pads rubbed out a harsh shriek, like metal screaming. She squinted and saw a group of morning joggers gathered at the guardrail of the Hudson River. Some people tied belts into rough ropes and shouted slogans to pull up. The sound seemed distant and chaotic in the fog. She took off her helmet, walked forward quickly, and roared: "NYPD! Disperse!"

Outside the guardrail, a dark gray windbreaker floated on the river, like a crow feather soaked in water, sinking and sinking in the cold waves. She pushed through the crowd and glimpsed the lifesaving box next to the guardrail. The door of the box was half open, and the shell was spray-painted with advertisements-"Sun Umbrella Bridge All-Weather Protection", the handwriting was crooked, as if it was painted in a hurry. The box was empty, with only a broken rubber band and a faded umbrella logo printed on the side. She frowned and cursed, "Guardian? Go to hell."

The drowning man was dragged ashore, and the ice water flowed down his face, dripping on the frosty ground, and instantly froze into tiny ice beads. This was an Asian man in his fifties, thin as a dead branch, with pale skin that was almost transparent. The wedding ring on the ring finger of his left hand shone faintly in the morning light, as if it was the only thing alive on him. Niu Aihua squatted down, unbuttoned his wet suit, and found that the second button of his shirt was a disguised miniature camera, and the lens cracked into a spider web, as if it was deliberately crushed by someone. She pressed his chest and shouted, "Breathe!" The man suddenly spasmed, and his skinny hands grabbed her wrists, his nails dug into the skin, and the pain made her grit her teeth. He squeezed out broken syllables from his throat: "Umbrella... Seventh floor..." His voice was hoarse like the wind blowing through dead leaves, and then his eyes rolled back, his head tilted, and he died.

The paramedic pushed her away, and three white drones flew low, spraying disinfectant on the body, which quickly formed ice crystals and wrapped around him like a strange film. Niu Aihua stood up, and the scratches on her wrists were bleeding, and it hurt like a needle. She stared at the flashing red umbrella logo on the tail of the drone, and the letter her brother left before he disappeared ten years ago came to her mind. The letter was hidden deep in her bedside drawer. The letter paper was yellowed and the handwriting was blurred, but the last sentence was engraved in her heart: "What they did on the seventh floor will destroy us." She clenched her fists, her throat tightened, and whispered: "It's you again, 'Umbrella'."

In the mist, morning joggers whispered, and someone whispered: "This guy looks like a professor." Niu Aihua turned her head, swept her cold eyes across the crowd, and growled: "Who knows him?" No one answered, only the sound of the wind whistling in her ears.

2. On-site investigation and physical evidence registration

The lights in the police station were dim, like the projector in an old movie theater, making people's faces look sickly waxy. Niu Aihua pushed the door open and walked in, her boots making the floor thump and bringing in a gust of cold wind. Jeffers leaned against his desk, holding a cup of cold coffee in his hand. When he saw her come in, he raised his eyebrows and said with a hint of teasing, "Failed to save someone again?"

"Dead." She took off her coat and threw it on the back of the chair, her tone as cold as ice, "Overdosed on sleeping pills and fell into the river."

Jeffers shrugged, sipped his coffee, frowned and complained, "This is the third one this week. Are New Yorkers crazy? Or is the river poisonous?"

She didn't answer, but walked to the evidence bag, put on gloves and looked through the remains of the drowned. A soaked family photo, the man in the photo was holding a little girl, smiling gently, the background was the clock tower of Cornell University, the edges of which were blurred by water; a gold-stamped black card with "S.U.C Consulting Group" written on it, and a small laser etching on the edge: "For use by Class B partners only." She ran her fingernails across the card, and the metal felt cold, as if it had been fished out of the river. She stared at the umbrella logo on the card, her heartbeat quickening, and her brother's voice loomed in her mind: "Be careful of the 'umbrella'."

"Check this." She handed the black card to Jeffers.

He took it and squinted: "Sun Umbrella Consulting Group? I've heard of it. It has sponsored many academic conferences and is quite high-profile." He paused, put down the cup, and said seriously, "You don't look right. What's wrong?"

Niu Aihua was silent for a moment, walked to the window, and pushed open a crack. The fog outside rushed in, freezing cold, like the chill of the Hudson River entering the house. She whispered, "Ten years ago, my brother disappeared. He was a neuroscientist. Before he left, he told me that he was studying 'dreams' and that they were the last secrets of mankind. The last time we contacted, he mentioned 'umbrellas' and 'seventh floor' and asked me not to worry about it, but he disappeared the next day." She turned around, her eyes like knives, "This guy said the same thing before he died."

Jeffers put down the coffee cup and frowned, "Do you suspect that the parasol has something to do with him?"

"I don't know." She clenched her teeth and pinched her nails into her palms, "But I want to find out."

Jeffers stared at her and sighed, "Your stubborn temper will get you into trouble sooner or later." He picked up the black card and looked at it over and over again, "Okay, I'll check it out. But you have to stay calm and don't dive into a dead end."

III. Autopsy report and preliminary analysis

When the report from the physical evidence department was delivered, Niu Aihua was sitting at her desk, holding her brother's old photo in her hand. That was their last photo together. She was wearing a police academy uniform, and her brother was smiling proudly. The background was the streets of Brooklyn, and the sun shone on their shoulders, like a dream that could never be returned. The report showed that the drowned man was named Zhou Ming, a professor of materials science at Cornell University. The cause of death was an overdose of sleeping pills. The blood drug concentration was so high that it was enough to make people comatose within a few minutes. She turned to the autopsy section and frowned: there was abnormal damage to the brain, the frontal lobe and hippocampus atrophy, like long-term high pressure caused by nerve failure, the note read: "Similar to experimental brain damage, no natural cause found."

Jeffers came over, holding the printed materials in his hand: "Overdose of sleeping pills? Suicide doesn't need to be so cruel, like blowing yourself up."

Niu Aihua stared at the report and said in a low voice: "This concentration is something that ordinary people can't bear. He may have fallen into the river after falling into a coma, not committing suicide." The scene before Zhou Ming fell into the water appeared in her mind: the bridge was foggy late at night, he staggered towards the guardrail, holding something in his hand, and finally fell into the cold river with blurred consciousness.

"Where is the camera?" Jeffers asked, pointing to the button device on the table.

"It may be evidence." She picked up the button camera, and the cracked lens reflected her cold face like a broken mirror. "He is monitoring something, or being monitored by something." A scene before her brother disappeared flashed through her mind: he was sitting on the sofa in the apartment, tapping his fingers on the table, and whispered: "They are monitoring me, Aihua, don't believe the surface."

She stood up and grabbed her coat: "Check his background, I'll go to the scene to take a look."

Jeffers called her: "Hey, it's getting dark, don't be stubborn alone! The visibility in this fog is less than ten meters!"

"No time." She didn't even turn her head, and the door slammed shut, leaving Jeffers shaking his head helplessly.

IV. On-site review and new clues

The wind by the Hudson River was as cold as a knife, blowing Niu Aihua's jacket rustling. She stood by the guardrail and swept the flashlight over the place where the drowning person was dragged up. The ice crystals on the ground had not melted yet, mixed with blood and frozen into dark red, like a weird painting. She squatted down and noticed that the screws at the bottom of the guardrail had been loosened, and there was a residue of transparent tape on the edge, with a few small metal wires stuck to it, like some kind of temporary device. She touched it with a glove and frowned: "Someone has moved it, it doesn't look like an accident." She put it in the evidence bag, and a vague hypothesis emerged in her mind: Was Zhou Ming pushed down?

In the distance, the Sun Umbrella headquarters building on the other side of the river lit up red, and the umbrella-shaped signal lights flickered in the fog, staring at her like an unsleeping eye. She stared at the light spot, her heartbeat quickened, and the memories of ten years ago came flooding back. After her brother disappeared, she checked the Sun Umbrella Company and disguised herself as a reporter to sneak into the headquarters, but was stopped by the security guard. A burly guy sneered and said, "Seventh floor? Miss, that's the machine room, no one can go up there. Don't meddle in other people's business." She had no evidence at the time, so she could only leave in disappointment, but the phrase "seventh floor" has since become a nightmare she can't get rid of.

The phone vibrated, and she looked down. It was an anonymous text message: "Don't check it. The seventh floor will kill you." The handwriting was rough, as if written by a trembling hand. She clenched the phone, her knuckles turned white, and looked up at the building, whispering: "Give it a try." She took a deep breath, and the mist penetrated into her lungs, cold as a needle. She knew that this was not a warning, but a provocation.

5. Memories in the apartment

Back in the apartment, Niu Aihua pushed open the door. The room was as dark as a cemetery, with only a faint light from the street lamp outside the window. She turned on the light, and her shadow was cast on the wall, like a lonely silhouette. She walked to the bed, opened the drawer, and took out her brother's letter. The letter paper was yellowed, and the edges were roughened by her touch. The ink was blurred, but the words "seventh floor" and "umbrella" were still dazzling. She stroked her fingers over the paper and whispered: "Brother, what did you see?"

There was another sentence in the letter that she didn't tell Jeffers: "If I disappear, don't look for me. They are more terrible than you think." She closed her eyes and recalled the last time her brother came to her apartment. He was wearing a gray sweater, his eyes were tired, and there was a red dot on his wrist. When she asked, he just smiled and said, "It's a souvenir from the experiment." After he left that day, there was no news, only this letter.

Outside the window, the street lights suddenly went out, and three black trucks drove by silently. The fluorescent words "S.U.C Logistics" on the rear of the truck flashed in the night, like the eyes of a ghost. She walked to the window, drew the curtains, and unconsciously pressed the electric baton on her waist, whispering, "You are here." She took a deep breath, and there seemed to be a hint of turpentine in the air, pungent and weird. She frowned and looked around, but the table was empty. She whispered, "Wait and see."