Puzzle box

Derrick fingered the small box that he carried in his off-hand, feeling the subtle dips in the wooden construction that gave away where the tricks were in the lock. The person who had made it for him had been a master woodworker, so the lines were nearly indistinguishable from the rest of the shape. But he was well familiar with it, and had opened and closed the box countless times since he had obtained it. He could find the lines and unlock the box in his sleep by now.

They were a series of sliding pieces, all of which served to lock one another in place, only able to move one in a direction at a time, and only in a very precise order. Some of the pieces were even only permitted to be moved at a certain distance, so if they were pushed all the way to their end, the next lock would be unable to move in the proper direction. It took a very intricate knowledge of the box to be able to complete the twenty necessary movements to open the box entirely - something that Derrick had memorized quite some time before, and that very few other people in the world knew. It meant that whatever he put in the box would be incredibly safe.

Of course, most people wouldn't be particularly comfortable knowing what he kept in the box as it was. After all, it certainly wasn't a very normal thing to be carrying around with him, and especially not in such a safe and secure container. But he carried with him ten very particular fingernails which he had acquired over his journey, each of which were very important to him for different reasons - reasons which he chose not to divulge to any who asked. They weren't magic, as some tried to guess, nor were they his own. They were not those of his victims, or those of people who had been particularly close to him.

In fact, he had no idea who they belonged to. He had found them, discarded, consistently over time as he stayed in inns. They were always in the center of his pillow when he entered the room, sitting there and waiting for him. The consistency of them suggested to him that they were all from a single person, and that thy were either insane or knew that he would be there the next night and were specifically leaving them for him. Either way, he wanted to know who they were, and why they were going exactly where he was.