AN: This is a sequel to an earlier story I wrote called "Steady Hands." I highly recommend reading "Steady Hands" before reading this story.

- O -

Don pressed play again. He'd watched the interview over a dozen times, yet he pressed play again. It was a routine he performed after a case became personal. He'd done the same thing when Colby was arrested for treason and when Amita was kidnapped by Duryea. Watching video of anything connected with the events held his focus and blocked out the rest of the world. It was a distraction, a drug to protect him from the pain. His own personal P vs. NP. This time, it was footage of his brother after Charlie had been forced to shoot a hostage.

"And then what happened?" the debriefing agent asked.

"They put the gun in my hand. They told me to shoot or they would kill Don."

Pausing the interview, Don ran it back and played the last line again.

"They told me to shoot or they would kill Don."

He ran it back again.

"They would kill Don."

He paused the tape at the moment his brother spoke his name. Charlie looked directly at the camera, expressive eyes full of concern. It was as if he were looking directly at Don, speaking to Don, sending Don a message. If only Don had seen it sooner, he could have prevented the tragedy that followed.

Picking up a stack of papers, Don flipped through them until he found the mugshot. It had been taken shortly after Charlie's arrest at the warehouse. The man in the photo looked nothing like the man on the screen. Six murders had driven the emotion from Charlie's eyes.

Setting down the photo, Don pressed play on the interview.

"What did you do?"

"I pulled the trigger."

Don paused the tape again. He replayed the line three more times, listening to the intonation and inflection of those four words. Did Charlie's voice quiver with excitement or fear? Was that exhale at the end due to exhaustion or anticipation?

He thought back to the first time he'd taken Charlie to a shooting range. He'd taught him how to hold a gun, how to maintain control of his breathing, keep his hands steady. He could still see Charlie's wide grin after hitting the target. His brother held out trembling hands. Look at that, he'd said, adrenal response.

"I pulled the trigger."

It was hard to believe that was the same man.

If only Don had been more aware. If he'd paid more attention after the events, maybe his brother wouldn't have turned into a serial killer. He should have known that the experience would affect Charlie so deeply. He should have gotten him help, spoken with him, prevented his desire to kill again.

Six murders. Charlie had committed six murders. Charlie, his geeky little brother, math prodigy, tenured professor, had become addicted to killing. Now he would spend the rest of his life in prison, and chances were good that a court would significantly decrease the length of that life.

Through the glass wall of the media room, Don saw his team watching him. He knew they were worried about him. They had been since they found the first body with Charlie's fingerprints on the murder weapon. They thought it was a mistake. Charlie must have been set up or the evidence tampered with. When the second body appeared, Don began to realize the truth. More bodies entered the morgue, more evidence collected, only one possible answer: Charlie.

"Don?"

He recognized Megan's voice but did not turn around.

"Don, you shouldn't be here. The assistant director told you to take some time off. You should be home with Allen."

Don snorted.

"Your father needs you, especially now."

When Don didn't reply, Megan moved farther into the room.

"This isn't your fault, Don."

Just like that, Megan had reached the real reason Don sat alone in the media room watching Charlie's interview on repeat. Don felt responsible for his brother's actions.

"I taught him how to shoot. I put him in a situation where he was forced to kill an innocent person," Don said quietly. "None of this would have happened if I had protected him better."

"Don, serial killers don't just manifest overnight. Most people would be sick with guilt after shooting an innocent victim. The fact that Charlie had the opposite reaction proves that there was something fundamentally wrong with him."

Don leapt from his seat, forcing Megan to step back. He glared at her with barely contained rage.

"Don't talk about him like that," he growled. "Don't you dare talk about him like that."

Megan reached around Don and picked up the mugshot he'd been looking at earlier. She held it up and Don flinched.

"You can't tell me that this is the face of a mentally stable human being. If this were anyone besides Charlie, you would not be defending him like this. You would not be blaming yourself."

Her words deflated Don's temper and he sunk back into his chair.

"You're right," he said to his feet. "I can't be objective in this case."

Megan knelt to capture his eyes. "No one expects you to be objective. It was precisely because of your knowledge of Charlie that we managed to find him. If you hadn't predicted his pattern, he'd still be out there killing. I'm not telling you to forget that he's family, I only want you to stop punishing yourself for his actions."

Don took the mugshot from Megan's hands. He forced himself to look at it.

"I should have seen it coming. I see killers every day. I should have seen the signs in him."

"You're still blaming yourself," Megan said.

He shrugged and set the mugshot back on the desk, face down.

There was a sudden commotion in the bullpen. Don stood up and looked through the glass wall in time to see two agents leading a small, curly-haired figure toward an interrogation room.

He felt Megan's hand take hold of his arm, a pre-emptive gesture.

"Don, you shouldn't be here for this."

Charlie disappeared with the agents and Don felt himself breath again. "I want to talk to him."

"You know you can't."

"It will be off the record. Nobody will have to know."

"It doesn't matter. You can't see him."

"Please, Megan."

"Don…"

Her voice quivered and Don felt a spike of hope.

"Please," he said. "Just give me five minutes with my brother."

Even though it went against all training and protocol, Megan found herself nodding.

"Fine. Five minutes."

They exited the media room and crossed the bullpen. Megan spoke quickly with Colby and David. Don saw her glance his way and nod. Soon the three members of Don's team were heading toward the interrogation room. A minute later, Colby and David reappeared with the agents that had escorted Charlie. Don suspected Megan stayed in the viewing room to monitor Don's conversation with his brother.

Don breathed slowly as he navigated the doors that eventually brought him to Charlie's room. He paused and collected his thoughts, making sure he was in control of his emotions, then pushed through the door.

Charlie was seated and handcuffed at the metal table. He looked surprised to see Don.

"Did the FBI change their rules on investigations involving family?" Charlie asked sarcastically.

Without answering, Don moved to the corner where the camera was recording. He reached up and detached the cable. He knew Megan was still watching, but now there would be no official record of his time with Charlie.

Don sat down opposite his brother. He forced himself to look into his soulless eyes.

"I only have a few minutes," Don said. "This will be the last time we speak."

"You won't visit me in prison. You won't come to see me before they execute me." He spoke in statements, not questions.

"I'm not going to contaminate my memories of you. I choose to remember you as my annoying genius brother who helped me save hundreds of lives. Not as the murderer who killed six people."

A wicked grin expanded across Charlie's face. Don couldn't help but remember Megan's words about something being fundamentally wrong with Charlie.

"Why speak to me now? What is so important that you risk poisoning your memories?"

"I need to know if I should feel responsible for your actions."

Charlie nodded. "That makes sense. You are blaming yourself because I chose to shoot a stranger instead of killing you. It's a logical solution to an equation. However, it is only a small segment of a much larger equation. And every time I killed, more of the solution materialized."

Don flinched and Charlie laughed.

"It's okay, Donnie. I don't feel repulsed by killing anymore. Taking a life isn't repugnant, it's elegant. It's a finality. Shooting a man in the back of the head, blasting a hole in his skull and sending a sliver of metal through his brain will result in death." Charlie leaned back in his chair, distant smile on his face, hands resting in their metal cuffs on the table. "It's the most satisfying solution I've ever experienced. The emotional release is better than any answer to a math problem. Even finding the answer to P vs. NP wouldn't compare to killing."

Don stood, feeling sick.

"You have your answer?" Charlie asked.

Don looked down at his brother. He pictured the events that brought them to this moment. He listened to Charlie's words about killing. Then he examined his own emotions and found what he wanted.

"Whatever reason you have for doing what you did, I am no part of it. Goodbye, Charlie."

Don didn't look at his brother again as he fled the room.

From the viewing room, Megan watched Charlie. She saw him stare straight ahead, dead eyes glued to the wall. The moment Don was gone, Charlie's breathing relaxed and she saw something flicker in his expression. It was only for a moment, but there was no denying the relief that crossed Charlie's face. No matter what happened to Charlie after this moment, he had saved his brother a lifetime of guilt.

And he knew it.