Howard calls the guys into the Mars rover control room on an emergency. He maneuvered the rover into a crevice, and he needs some help from Sheldon and Raj to maneuver it out. Leonard's task is to get Stephanie, the girl Howard sneaked into the control room, out of the facility, she who doesn't have clearance to be there. On Leonard's task to drive Stephanie home, Stephanie and Leonard hook up. She's a medical doctor with a high libido. Despite Stephanie's assertion that Howard had no chance with her (she went with him since he told her she could drive a car on Mars), Leonard feels guilty, especially in that he wants to see her again. What makes it worse for Leonard is that he knows that Howard still thinks he's dating her. Leonard has to figure out what to do to reconcile dating Stephanie while still being friends with Howard.