The world went silent.

For a brief moment, it felt as though everything had stopped - the sounds of chaos, the screaming, the alarms - all of it vanished, leaving behind only the rhythmic pounding of Lena's heart.

She stood over Theo, his blood staining the cold, sterile floor beneath him. The scalpel was still in her hand, slick with his life.

Theo gasped for breath, his face contorting in pain.

"You - " he coughed, his voice barely a whisper, " - should've left."

Lena's eyes were hollow. A storm of emotions flickered in them, but there was no room for mercy, no room for the girl who used to love him. She had become something else.

Her grip on the scalpel tightened. "I couldn't. You taught me too well."

Theo tried to lift his head, but his strength was failing him. His blood pooled around him, mixing with the dust and debris from the explosion. "You're not... free... until you stop."

"Stop what?" she asked, her voice like ice. "Killing? Or remembering?"

She took a step closer, the scalpel gleaming in the dim light as the fire alarms continued to shriek in the background.

Theo's eyes widened, desperation flickering in them. "You think I did it because I wanted this? Lena, it's... it's the disease. It's in us. It's... you - "

Lena bent down, placing the blade against his throat. "Don't talk about what you don't understand."

He reached up weakly, his fingers brushing the side of her face, a final plea, a final attempt to reach the sister he once knew.

But she wasn't listening anymore.

The years of games, of manipulation, of betrayals - it was all too much. She had become something far more than just a student of medicine, of healing. She had become a creature of precision, of survival.

In one fluid motion, she slashed.

Theo's last breath left his body, the sound of it a final echo in the room.

The pain of their past, the trauma of their shared upbringing, all of it died with him.

---

Outside, chaos reigned.

The building was on fire, the explosion shaking the very foundation of the university. Sirens screamed in the distance, police and emergency teams flooded the campus, but none of it mattered anymore.

Mikael stood at the entrance of the surgical wing, watching the flames rise in the distance, his gun at his side. His expression was unreadable, but the tension in his shoulders spoke volumes.

He knew the end had come.

He saw Lena emerge from the shadows, her clothes torn, her face streaked with blood. Her eyes were empty, cold - far removed from the girl who once loved her brother.

"Is it over?" Mikael asked, his voice low.

Lena didn't answer at first. She just stood there, her gaze distant, her hand still clutching the scalpel. Then, finally, she spoke.

"It's over."

---

Elsewhere, in the wreckage...

Dr. Park had escaped through the tunnels just before the final blast, slipping away unnoticed. She had no intention of sticking around to see the aftermath. The plan had been simple: survive.

She had done more than that. She had watched them all burn.

Her eyes flicked to the horizon where the university's towers once stood tall. Now, all that remained was smoke and ruin.

Her heart was calm.

The world had fallen, and she was the only one left standing.