A police officer who is also a serial rapist, uses his position to lure victims. The rapist is being sought by Don and his team. Don and Megan experience difficulties with a female Internal Affairs Officer from the LAPD who jeopardizes the investigation by jumping to conclusions and browbeating witnesses.

Meanwhile, it's a full house for the weekend at the Eppes family home as Alan has invited Dr. Larry Fleinhardt for the weekend without knowing that Charlie has invited Amita to spend the weekend because her residence is being fumigated. Larry asks Amita to join him on an important project and is relieved when Charlie enthusiastically supports the idea.