Spot Hidden

Spot Hidden is the skill that Tom McGee tells his players to use for investigative tasks, but he also has them use it for other things such as for insight checks, which is odd since a listen check can be used for being more aware, which can allow the character to understand that someone may be bluffing. Spot Hidden is used strictly for spotting hidden things on the outside world, not hidden emotions. Tom can however risk irritating fans by playing the way he wants, which is fine. Be wary that he may frustrate you since he doesn't know as much about Call of Cthulhu than he does Dungeons & Dragons.