PICK OF THE WEEK TV extra Californication star McElhone is a woman on a mission – to Mars

Lego Masters (C4, 8pm)

remaining three chefs face Marcus’ test – to cook a cauliflower steak with two cauliflower garnishes and a nut butter. Finally all six participants can redeem any earlier mistakes when they cook their own signature dish.

Melvin Odoom presents a fresh run of the contest to find Britain’s best amateur Lego builders, as teams aged nine and up are given access to a room full of the tiny bricks. They are challenged to come up with all manner of models to put their creativity, construction skills and imaginations to the test. Design executive Matthew Ashton returns to assess their efforts and is joined by new regular judge, engineer Fran Scott.

She’s 82 and He’s 39: Big Age Gap Love (Channel 5, 10.15pm)

The first of two documentaries about people in age-gap relationships introduces viewers to Andy and Beth (47 and 19), who had to move away from their home town after disapproving family and friends learned about their relationship. Laurence (62) and Sam (26) discuss how they came out twice – once for being gay and again for being in an age-gap relationship.

WEDNESDAY Paul O’Grady: For the Love of Dogs (STV, 8pm)

This week at Battersea Dogs and Cats Home, Paul O’Grady attempts to nurse back to health the most badly injured dog he has ever seen, a saluki. As part of his rehabilitation, Paul takes him to a retirement home where the dog is showered with some much-needed love. Meanwhile, Paul tries to find a home for an elderly, dentally-challenged Shih Tzu, and he is also faced with the prospect of de-fleaing a stray Yorkshire terrier puppy.

The Apprentice (BBC1, 9pm)

As the sixth week of the contest unfolds, the candidates are challenged to devise a marketing campaign for a new budget airline, including making their own 30 second advert for television, and designing both a distinctive brand and a uniform for staff. Creating an advert for a business airline on board an aircraft brings disastrous results for one team, and both teams struggle when they have to pitch their campaign to industry experts. Back in the boardroom, Lord Sugar decides which candidate will be leaving the competition.

Dark Heart (STV, 9pm)

DI Will Wagstaffe and his staff investigate the mysterious death of a young nurse on the London Underground. While CCTV reveals the victim fleeing an invisible assailant, forensics find a DNA link to a missing teenager presumed dead for seven years. Aided by his new team DS Rob Mullan, DC Ray Monk, DC Annie Webb and pathologist Dr Luke Paul, Will unearths a bond of secrets and betrayals that leads him straight into the dark underbelly of the city.