Theodore was far more familiar with death than most people, and in fact, had been present for almost every single loss. His mother, most of his patients, and now his father. He would never claim to be unafraid or unaffected by it, but he knew that he could process the emotions (among them, guilt, more present than ever in this particular situation) and come through them alright, because he had done it before. He would not be unscathed, or unhurt, but he was strong enough not to let any of it bring him to his knees.
It helped that there was no unsettled business between him and his father, so far as he knew. They had been distant since his mother's death, but he knew that his father had loved him, and he knew that his father had known the sentiment was returned. He knew, too, that his father had known how Theodore would handle his eventual death, knew that he was capable of dealing with whatever was left behind. He took comfort in that.
"The obvious places to look are the ones we both have sentimental attachments to," he said. "Or the ones that I would think of, when searching for something of his. His study, his bedroom, the places where my mother's things are kept - maybe my old bedroom," he listed them as they occurred to him. "Those are the places anyone else would look, but I don't think it can hurt to try them, all the same."