Mel's parents come to visit and throws everything off balance.

Nathan faces a life-changing moment of truth - the operation to donate a kidney to beloved grandmother Chel.

With the Top 10 performing tonight: Michael Grasso, Christina and Ali, Studio One Young Beast Society, Taylor Mathews, Jeremy Vanschoonhoven, Anna and Patryk, Fighting Gravity, Prince Popycock, Michael Grimm and Jackie Evancho all have their hands full with the pressure that comes with the position. Each act is sensational but is it enough to get the 4 coveted spots for the Top 4?

When ex-Warehouse agent Rebecca Sinclair brings them an unsolved case involved a newspaper editor who murdered his wife and three secretaries in 1961, Pete and Myka use H.G. Wells's time machine to travel back and try to determine what artifact was used. Meanwhile, Artie refuses to trust Helena, the newest Warehouse agent.

Neal decides to arrange a con to get to Kate's killer, after Peter and Neal's search makes progress.

The kidnapping of Abel has left the Sons reeling, especially Jax, whose grief sends him into even deeper turmoil about his future with the MC. Gemma, having been framed for murder, stays on the lam and finds out some unexpected news from her past.

An Iranian trade delegate who escaped his handlers approaches the CIA to cut a deal. In exchange for entry to the United States, he is willing to hand over stolen intelligence.

Tim Gunn

After an exhausting morning getting his girls ready for school, Louie lets a fellow dad at his daughter's school train him at the gym, where he proves to be in worse shape than he thought.

Anthony Romero

On an aimless night out that his babysitter awkwardly talks him out of cancelling, Louie decides to break his rut by hanging out with a couple of black comics. After feeling completely out of place at a club, he ends up going to the Eastville Comedy Club to do a short set, then home to his kids for an early-morning pancake breakfast.

Actress Katie Holmes; TV personality Rick Harrison.

Carey Mulligan, Meghan McCain, Hans Staples

Henry wakes up on the rooftop of The Elysian apartment block, with memories of past glories starting to flood back in his dreams. Feeling more alive than ever, he sees the opportunity to be reborn via the magic of the internet and with Suzy's help contacts his loyal followers through a fan website.

In this episode, the team investigate the recent Gulf of Mexico oil disaster. Zoologist Liz Bonnin travels to Louisiana and takes part in the rescue effort to protect the area's wildlife, while Jem Stansfield builds a scale model to explain what happens when an oil well gets out of control, and how to solve the problem.

Meanwhile, Dallas Campbell proves Einstein's theory of relativity with the help of a jet plane and a very expensive atomic clock.

A new sexual health initiative is run at the school which includes a confidential emergency contraception service. Some of the staff and parents aren't happy with it though. Ronan and his girlfriend, Sarah, are worried as the condom they used split as they had sex, but while Ronan wants Sarah to take the morning-after pill, she's too scared to ask the nurse for the pill. When Jess also needs the pill she ends up persuading Vicki to get it for her. After the nurse refuses to give Vicki the pill when she realises it is not for herself, Vicki and Jess end up in an argument and Vicki blurts out about Jess sleeping around in front of Chris. Karen and Charlie acknowledge his affair and Charlie wants to try and save their marriage.

When a cowboy fair is organised by the Wild West Society in the village of Ford Florey there ends up being a dispute over some land. Jack Fincher and Silas Burbage both claim that the Swamp belongs to them and Dan Malko wants to buy it and create a travellers' site. When the dispute ends up with a murder being committed, Barnaby and Jones are called in to investigate.