Based on practically no information and no medical history about a mystery patient sent by the CIA, House is using some unorthodox methods to diagnose and treat him. Meanwhile the remaining candidates are questioning Foreman's judgment.
Alan pushes a temporary-insanity defense when Patrice is accused of killing the man who murdered her daughter; Denny finds fault with an associate's physique; Jerry helps a kindred spirit find a personal treasure.
The team suspect their own colleagues after the burnt remains of an intern at the Jeffersonian are discovered. Meanwhile, Booth poses as Cam's boyfriend at her family get-together.
Benson comes under fire from fans of a convicted serial killer after a body turns up that greatly resembles his work.
MI5 has to intercept a Russian arms dealer who plans to pass blueprints for a nuclear device to Iran. Adam and Ana decide to bring their relationship to a close.
Jonesy keeps pranking Jen, much to her dismay, so Jen tries to get revenge on Jonesy by fighting fire with fire and pranking him badly. Meanwhile, Caitlin also apparently wins a contest from the bank that gives her money to spend. She then spends it on some diamond and earrings that makes Tricia believe that Caitlin working in the lemon is fake, which causes Tricia to stalk Caitlin. (Aired as a Viewer's Vote episode.)
When career criminal Wolfgang West gets put away for four years, his wife Cheryl decides it's time for her family to go straight. But can the Wests change the habits of a lifetime?
Gibbs finds himself emotionally challenged when he agrees to investigate a crime connected to a friend of his daughter, who passed away years ago, and the investigation leads to a shocking conclusion.
Sam and the crew go after a thrill-seeking pair of escaped souls that engineer car wrecks to keep their relationship fresh. Meanwhile, the Devil tries to set Sam up with a new girl.
Sean and Christian learn about the glamorous side of fame and the price that many are willing to pay for it. Julia visits Sean, Christian and Liz in Los Angeles with a surprise announcement.
Five teenagers must locate and secure ancient relics with unbelievable power, while at the same time stop a demonic corporation who want the relics for their power.
The investigation into a runway model's death leads Horatio to his son and his nemesis.
After still being convinced that Maya is not dealing with her loss, Joan decides to take Maya on a shopping spree to help her recover but surprisingly, Joan realizes that she is the one who needs therapy because of Aaron departure to Iraq. Meanwhile, Monica tells William that she is pregnant but his reaction is unlike she expected.
Barbara returns to town with news that could have Russell very happy.
Since Samantha has no memories of the past, including her sexual experiences, she is faced with the decision of waiting this time for the right guy to come along, or to experiment.
After Alan and Charlie have a fight about Alan's role in the house. Alan packs Jake up and moves in with his mother.
Peter and Caitlin learn about the endstage effects of the Heroes virus. Many of the Heroes work together to fight the Nightmare Man. West is shocked to the identity of Claire's father. Hiro and Kensei's journey comes to an end.
It's Martin's wedding day and he manages to offend the vicar who is due to conduct the ceremony by suggesting he has a drink problem. When they struggle over a bottle of whisky, the vicar falls over, fracturing his pelvis and Martin has to find a replacement. Pauline suggests the former vicar of Delabole, who strikes a deal. He will conduct the wedding ceremony if Martin will examine his sick pig. Bert and Al are putting the finishing touches to the wedding banquet when disaster strikes. Last in the series.