100 Years Younger in 21 Days, STV, 9pm

THE end is in sight for the eight well-loved and well-worn celebrities taking part in the unique experiment to find out if we really can stop the ageing process. June Brown, Claire King, Roy Walker, Sid Owen, Sherrie Hewson, Shaun Ryder, Russell Grant and Sandra Martin are subjected to more scientific testing to discover how well, or badly, they are ageing, inside and out. Tonight they learn all about their brains and how they are key to ageing well. Mindfulness and meditation sessions are led by Coronation Street stalwart Bill Roache, during which Sherrie makes an emotional breakthrough

Shetland, BBC 1, 9pm

FOLLOWING Jo’s assault, the team is devastated. While Sandy feels guilty for not protecting her more, Jimmy tries to keep everyone focused, but pressure mounts on him to re-arrest Malone. However, in the absence of evidence, Perez resists. Adding to his stress, DI Cole and DS Jackson from the MIT arrive and begin picking holes in his investigation. Stunned that a search of Malone’s farmhouse has not been carried out, Cole and Jackson conduct their own. However, when they arrive, Malone is nowhere to be seen.

The Ruth Ellis Files: A Very British Crime Story, BBC 4, 9pm

THE case of Ruth Ellis, the last woman to be hanged in Britain, has long fascinated the public and has caused controversy. However, the crime for which she was convicted, shooting and killing her lover David Blakely in 1955, has always seemed open and shut. In this new three-part series, filmmaker Gillian Pachter takes another look at the murder and investigation to see if Ellis really received justice.

Back in Time for Tea, BBC 2, 8pm

WE’VE come to the end of this social experiment, so the Ellis family reflect on their time-travelling adventure over the past few weeks. They explore how the legacy of 100 years of history lives on in the northern diet today. Lesley and Sara Cox visit a Liverpool bakery, and sisters Caitlin and Freya examine how recent changes on Manchester’s Curry Mile affect peoples’ evolving relationship with flavour. Finally Sara and northern chef Rob Owen Brown prepare a celebration meal.