New Tricks (BBC1, 9pm)

WELL, you heard it here first. I stuck my neck out and predicted that one of the BBC's most popular series would not survive the departure of the last remaining member of the line-up: James Bolam, Alun Armstrong, Amanda Redman and Dennis Waterman.

I don't know about fat ladies, but the signature song singing Waterman is leaving, and although Larry Lamb is joining the creaking ranks of the Unsolved Crime and Open Case Squad (Ucos) this uniformly good cop show is in its final run.

Waterman, who bows out of this 12th season as Gerry Standing in a two-parter start, admits that he struggled when North-East actors Bolam and Armstrong bowed out, closely followed by Redman.

"I'd already signed up for the next season. I did ask Amanda if I'd look sad carrying on after everybody else had quite and she said, 'Don't be daft'," he says, claiming that a new house purchase left him needed the money.

As they left, Armstrong and Redman ignited a row over having to improve scripts by improvising the words. Waterman has patched up ill-feelings with writer/director Julian Simpson, but confesses being bugged by the new character Danny Griffin, played by Nicholas Lyndhurst – who stars in the last ten shows with Tamzin Outhwaite and Denis Lawson.

"Nick's playing a genius who knows everything. There was one episode where overnight he teaches himself to play football and I thought that was ridiculous," says Waterman.

The strange case of New Tricks began back in 2003 when audiences loved a pilot show, but the BBC didn't. The old retired dogs of the Met were so popular that it become the Beebs most popular programme in 2008.

Waterman says he has had no idea New Tricks was becoming old history until after he'd quit.

"I think it's that you can't cast chemistry. I've been unbelievably lucky with who I work with. You wouldn't think I could have more fun than with John Thaw on The Sweeney and then they came up with George Cole for Minder... blimey. Then I worked with Jan Francis on Stay Lucky and then the New Tricks bunch," he says.

Tonight Ucos investigates the death of a policeman whose body has lain untouched in a basement for 30 years.

The investigation reveals details of Gerry's own murky past.

Waterman is satisfied with his departure. "My only concern, rather conceitedly, was that the stories had flashbacks of myself as a young man – and anyone who has seen The Sweeney will know exactly what I looked like back in the 1970s. But they cast a great young actor called Samuel Oatley for the part and I'll let the audience judge how alike we are."

Abducted (ITV, 9pm)

EVERY 12 hours a child in the UK is taken by a parent or family member, with the guardian left behind often going through years of heartache and red tape just to see them again. This documentary follows three parents on emotional and dramatic journeys as they fight their ex-partners through the international courts in a bid to get their children back from foreign countries. With access to a team of child-recovery experts, the film reveals how some parents are taking desperate measures. Narrated by Paul McGann.

Hair (BBC2, regions vary)

IT'S the grand final of the hairdressing competition, and the remaining contestants have to prove they are capable of creating a style that will make someone feel special on what is supposed to be the happiest day of their life. First, presenter Katherine Ryan and judges Alain Pichon and Denise McAdam head to London's funkiest wedding fair, where the three finalists have to dream up avant garde bridal hairstyles for the models who will be taking to the stage in front of 900 invitees, showing they can think beyond classic updos and delicate braiding. Then they face the arguably more difficult challenge of giving real brides the wedding day hairdo of their dreams.

Viv Hardwick