Psych: Season 3, Episode 12

3 - 12: Earth, Wind and... Wait for It

An arson investigator (Milena Govich) gets no help when she suspects that a recent fire was the result of arson and not an accident, but all it takes is Shawn's intervention to reveal that an arsonist/murderer is on the loose, so he and Gus infiltrate the firehouse that put out the fire to find out how deep the case really goes.