A/N: There have been quite a few post-finale fics posted, but I wanted to take a shot myself. I wrote this the night of the episode and just got around to finishing editing it. Spoilers for 1x11, and vague references to 1x07. Thank you for reading!

Henry didn't leave his cave for five days. After the police finished processing the scene and interviewing Henry and Abe, Reece put Henry on mandatory leave, until further notice. Ordinarily Abe would have been grateful for that, but he knew that without work, his father had no reason to leave their apartment. Not now anyway.

Abe also knew that if there was one place Henry didn't want to be, it was his "laboratory." Secluding himself to the room he now most despised wasn't something Henry enjoyed doing. Abe knew him well. He recognized this behavior—he'd seen it before; Henry was punishing himself.

For a man who lived outside the laws of physics and nature, Henry considered himself beyond the typical human means of penance as well. Henry wouldn't be prosecuted for his actions—nor did Abe, or any person in their right mind think he should—but his father didn't see that as just. He was drowning in guilt. Isolating himself in the very spot his misdeeds occurred was the only way he could gasp for breath.

As the only person alive who had known Henry this long, Abe knew better than to intrude on his introspection immediately. Henry was pensive to a fault, and often required time to process his thoughts without interruption. Without outside interference. If Abe tried to reach him when he wasn't ready, he'd achieve nothing more than a dent in a brick wall.

So for five days he let Henry be. He brought him food and tea and made sure his father took care of himself physically, but he didn't say a word about anything important. Abe didn't know a single person his own age who wasn't patient, and living with an immortal most of his life had honed that virtue in Abe more than any other. He waited. But five days was enough, and honestly, Henry's intense reverie was getting more worrisome than usual. On the fifth day of brooding, and a week before Christmas, Abe took the steps down to his father's lab with a purpose.

Henry was sitting at his desk, where he usually resided these days. To appease Henry's meticulous nature, most every detail in the room had been put back into place since that night. The only discrepancy was the absence of Abigail's photograph in its usual location. Henry couldn't bear to look at it.

Abe knew Henry had noticed his arrival; his posture had tensed with the creaking from Abe's walk down the steps, and only relaxed when Henry noted his son out of the corner of his eye. Henry was ignoring him, but Abe wasn't going to be so easily deterred. Not today.

"You know, Mom told me a story once. I haven't thought about it for years, but I think it's relevant here."

Henry's breath hitched. His eyes involuntarily glanced to the spot where Abigail's picture used to be, then darted away. Abe had his attention.

Abe pulled a chair from the corner and sat down in front of his father. Henry's hands were folded over one another in his typical nervous fashion. Abe had observed the habit from a young age, and used it to read his father when nothing else worked. At this point, though, he didn't need to read Henry. He just had to reach him.

"I was maybe…ten or eleven. You were working a late shift at the hospital, so it was just the two of us home. I had a nightmare."

Henry reacted slowly, but in the manner Abe predicted. He blinked free from his hazy pondering, bringing his eyes up to face his son. He inclined his head just slightly, indicating that he was listening. Henry might be reluctant to discuss his own problems, but he would always lend an ear for the troubles of others. Especially the people he loved.

"I don't remember exactly what I dreamed." Abe chuckled. "Heck, I couldn't tell you what I had for breakfast two days ago." He tapped the side of his head. "This isn't what it used to be. But that's not important. It's…" Abe gave a heavy sigh. There were so many things he longed for his father to understand. It might be foolish to think that a man of seventy could offer life lessons to one a century and half older, but immortality, Abe had observed, was often blinding. Sometimes the simplest truths were tucked away in plain sight, but if you've been staring for too long, you're never going to see them.

"Abraham…"

"I know that I was scared. Terrified, frankly. And nothing Mom said could console me. Until she started telling me about a superhero. And not the kind with tights and a cape either. No, no, no. She told me a story about a selfless, brave man who would do anything to protect his family. Anything."

By ten, Abe was past the age of fearing the boogie man or monsters under the bed. A make-believe protagonist who could fly and shoot lasers wouldn't have done anything to quash his nightmares, but something more realistic would. Something that would protect from the real dangers of the world. Make him feel safe. Someone.

"I knew before long that she was talking about you, but that made it all the better. I fell back asleep and that was that. It's not the actions of a person that convey who they really are, Dad."

Henry inhaled sharply, making direct eye contact with his son for the first time. Abe hadn't called him by that name regularly since he was a very young adult. By that point, they both agreed it was too dangerous. It'd raise too many questions. It had pained Abe greatly at first, as if giving up the moniker dissolved their relationship too. He soon realized how wrong he was, but more importantly, that he could return to such sentiments when he really needed to. When Henry needed to hear it.

"It's their reasoning behind those actions. Their ideals. Values. What the person stands for and stands up against. Your stalker wants you to become bitter and warped and insane just like him, and he thinks by making you do what you did, he won."

"And how is he wrong?" Henry demanded. He blinked harshly, combating the tears forcing their way into his eyes. Abe would be lying if he said his own were still dry. "I killed a man, and not even a man who could come back to life afterwards. He's dead by my hands!"

"Listen to me. Listen right now." Abe placed his arms on the desk between them, leaning close to Henry. He ingrained every ounce of strength he had into his words. "Adam succeeded in making you kill that man, yes. You killed him. But you didn't murder him; there's a difference. Murderers kill for revenge or anger or just because they can! You know that. You know everything there is to know about murderers. And I know that you aren't one of them." Abe heaved a few deep breaths. Henry was staring at him, hanging onto every word. He wanted to trust what he was hearing—desperately. More than ever before, Abe could see just how lost Henry was. His father was terrified of himself.

Henry and Abe sat in silence for no more than minute, yet long enough to make Abe reevaluate how long sixty seconds actually was. When Henry spoke, it was barely above a whisper. His voice was shaky and pained. "How do I know I won't ever become one?"

A week ago Abe wouldn't have had a definitive answer for that. His father was by no means someone who could ever achieve that degree of evil, but Henry was a man of science and he needed proof. A week ago, nothing Abe could've said would have settled Henry for certain.

"Tell me, what was the first thing in your head when you realized that man was here? What came to mind immediately? Instinctively?"

Henry sighed in reverence. He pressed his face into his hands. "You. I didn't know where you were. I thought you were injured or…"

"Exactly. Your own interests were the furthest concern from your mind."

"I'm immortal, Abraham! He was no threat to me—"

"Ah." Abe held up a finger to silence Henry. "You may not be able to die, but you can still be hurt. Tortured. But that's not the point. You heard me come inside, and you engaged in a physical altercation with the man, which you hadn't done before that moment. Why?"

"I didn't want him getting to you. If he had stabbed me with the sword, so be it. But with you there, I had to get the weapon out of his reach."

"And you couldn't do it. So you grabbed something else. Your letter opener. If I wasn't there, would you have even considered picking it up?" Like a lawyer in court, Abe knew not to ask certain questions unless he knew the answer already. On this, he was one hundred percent positive.

The notion came as somewhat of a revelation to Henry. He leaned back in his chair, and took his first unrestrained breath in five days. "No."

"And there you have it. That's the largest discernible difference between you and Adam, and the reason you can never be like him. He kills because he wants to. He enjoys it. He feeds off the pain of others. You killed despite wanting nothing more than to avoid it, for a reason that Adam is incapable of." Abe stood up, pushing his chair back to the place he'd found it. From the dumbfounded expression Henry wore, he'd done his job. His father's face wasn't still drenched with guilt, but consideration.

Abe placed a soothing hand on Henry's shoulder and gently kissed the top of his head. It was a gesture that had comforted Abe countless times in his life, in a way only a parent could manage. From innocuous scrapes on his knees as a child, to the demons of war that haunted him following Vietnam, to the worries of days like today, it always gave Abe peace. Above all else, it was a reminder than no matter how old they were, where they stood, Henry and Abe's relationship wouldn't change.

"Dad, there is something sacred in killing to protect the people you love. Don't forget that." Abe squeezed Henry's shoulder, then returned to the staircase. On the third step his father's voice stopped him.

"Abraham." He glanced over. Henry wasn't smiling, but he wasn't frowning either. "Thank you. I suppose…I needed to hear that."

Abe nodded. "I know."

"You did what you did not for yourself, but for us. For your family. You'll get past this."