The first place Sam wanted to look for clues to Peter's disappearance was Peter's apartment, and luckily, he had a key. As he made his way into the building, Sam couldn't help but smile as he remembered how Peter had given him the key, just handing it to him without any warning, without fanfare, like it wasn't a big deal to say "Here, this is my space and now it's yours too, whenever you want it to be." That was just the way Peter did things, and the stinging sensation that memory created in Sam's chest was a reminder of how important it was to find Peter, no matter what he had to do. Even if he didn't find anything in the apartment, Sam was glad that he didn't have to worry about finding a place to sleep while he was here, and surrounding himself with Peter's things would definitely fuel
Sam unlocked the door and went inside, closing and relocking the door behind himself. It wasn't until he turned around that he realized he wasn't alone, and all he could do was stare in disbelief.