Therein lied the problem. Any mark left had a good chance of being gone come breakfast. Even if they caused injury enough to still be visible by then, there would be so many others injured that it could easily be passed off as a wound caused by a monster.

Still thinking, he moved back to the bed and sat down on the edge, hand to his chin. "You're right." He frowned. "There has to be something... A tattooed marking, maybe. Something that will stay."

There were those that still had some variety of special ability in this place. Magic of some sort. If need be, they could try and get one of them to help, but the fewer number of other patients they ended up relying on, the better.