Mark Berry

Sheldon heads to Las Vegas to win money for science. Meanwhile, Amy is taken wedding dress shopping by Penny and Bernadette, but her choices see them fall into a web of lies.

Leslie and Ben start new jobs; Donna, April and Andy prank Ben; Ann and Chris consider the future.

A maths genius is recruited by the FBI to solve complex criminal cases. When a serial rapist turns to murder, Charlie employs an equation to identify the killer's next move.

The team tackles a strange case, involving a suspect who impregnates young women before killing them.

Mickey pushes back into Bunchy and Terry's lives. Ray obtains a hip hop artist for his rapping neighbour, Ezra holds a fundraiser, and Mickey is approached by an FBI agent.

The body of a petty officer is found on a golf course, and McGee tries to locate a key witness with the victim's ham radio; Palmer looks to his co-workers for donations to a charity building playgrounds for children.