Chasing Shadows (ITV, 9pm)

THE days of Royston Vasey (the fictional town named after Middlesbrough’s Chubby Brown) may be over, but there may still be a reunion of the League of Gentleman, which is about to celebrate its 20th anniversary, says Reece Shearsmith.

Let’s hope that’s true because it means more work for League of Gentlemen colleague, Sedgefield-born Mark Gatiss. Meanwhile, Shearsmith is using his ability to create quirky characters by turning serious and starring in a new cop show as DS Sean Stone, who has alienated just about every colleague with his obsessive honesty and ended up in the missing person’s unit.

The role follows Inside Number 9, the series he wrote and starred in with Steve Pemberton, and roles in the horror movie A Field in England and on the small screen in The Widower.

"I'm probably what you would describe as a character actor and I do immerse myself in the parts," says Shearsmith. "I don't get recognised a lot because I'm usually disguised on screen.

"I quite like the level I'm at where I can have a normal life and walk around. The work is the thing that speaks for me. I'm not really a personality, I just do the acting and that's what I want people to see."

Although Chasing Shadows falls into the trap of linking its plots to serial killers (although fortunately not about a serial killer who kills serial killers) the actor hopes that the four-parter will be quickly re-commissioned. "I'd love to do more. I think it's only the start of what could be a really interesting journey for all of the characters. There are so many stories that could be told."

Alex Kingston co-stars as profiler Ruth Hattersley, who learns to deal with Stone's odd quirks and habits, and helps him build a team with their boss DI Prior (Noel Clarke). Their first case involves the disappearance of 16-year-old schoolgirl Taylor, and will be told over two episodes. Soon the trio are facing the difficult world of teenage suicide and someone who might be manipulating these tragic outcomes.

Paul O'Grady: For the Love of Dogs (ITV, 8.30pm)

BATTERSEA Dogs & Cats Home, in London, really fell on its feet when one of TV's sharpest celebrities agreed to host these doggy tales of derring-do. Paul O'Grady and his "pog-dog" moments starts with a touch of puppy love, as he gets to name four newborn labrador crosses – one of whom he leads astray with a trip to the pub. Meanwhile, an overweight Jack Russell's love of cheese is going him down a decidedly unhealthy path, and an anxious couple finally think they've tracked down their missing rottweiler, who has been missing for a year.

Castles in the Sky (BBC2, 9pm)

THE creation of Britain's radar system during the 1930s is little-known because this Battle of Britain success story was kept top secret and makes this programme all the more compelling.

It charts how Robert Watson-Watt (Eddie Izzard) and a team of relatively unproven and unknown scientists managed to put together a system of aircraft detection which was so cunning it was actually dismissed by many in the Oxbridge-dominated establishment, who failed to grasp its importance. Among them was none other than Winston Churchill (TimMcInnerny). With Watson-Watt and his team labelled as a bunch of "weathermen", they had their work cut out getting heard. Eventually, though, they began to get their work recognised – although not before striving against the kind of odds which permanently damage personal lives and marriages.

Laura Fraser and Julian Rhind-Tutt are also on the programme's radar.