Memento

Eiro, in his disguise as this young man, made his way out of the rock wall that he hid the Guard in, and then stepped back into the prison. He always kept the exact way that the new Guard had been moving in his mind. Usually it wasn't the bigger things, like if people heard Eiro say something wrong or if they saw him do something he wasn't supposed to, since a lot of the time you could simply explain it as an awkward mistake on his part, or he could simply try and lie about it in a casual way.

The things that often made people feel that something was wrong were the little things. If Eiro's mannerism or language used were off while he was trying to copy the Guard, he may not be found out right away, but it would be harder to get away with anything at all. People would double-guess certain things that they wouldn't if Eiro had just added these smaller things into the mix believably.