given by the bartender

in the tunnel on the way to dad's electronics, push a loose brick off the wall

in the museum, head backwards through the doorway after you exit the elevator going all the way down (wawel museum underground temple)

complete the board game (three in a row) on the other side (using the picture on ally's computer, and the papers on steve's desk)

complete the entire game > investigation mode > look at the investigation board in the police station > write down the cheat code that's on the paper in the top left > enter investigation mode in that chapter > after completing the mouse game entirely, put in the code after the screen says "somewhere in the room, a lock has opened"