Stonemouth (BBC2, 9pm)

NEW two-part drama Stonemouth is based on a novel by Dumferline-born novelist Iain Banks and was partly filmed in Macduff, Aberdeenshire (which stands in for the fictional Scottish town that gives the romantic thriller its name), and aired on BBC1 Scotland on Monday.

In spite of that the two leads, Christian Cooke and Charlotte Spencer, are actually English, but co-star Peter Mullan doesn't hold it against them. "Back in the day, I would have been less happy to see two English actors play two Scots. I wouldn't have been happy with that in the past, in fact I wouldn't have done it to be honest. But thankfully since Robert Carlyle, Ewan McGregor and Kevin McKidd and obviously now James McAvoy, these great actors proved that you can play any part and not just Scottish," he says.

He adds: "In the past 15 to 20 years, you've got Scots actors playing English characters with nobody raising an eyebrow, and the other way around, so I don't have an issue with it. In fact, I was in awe of Christian and Charlotte, who were absolutely spot on and had faultless Scottish accents."

Tonight's opener sees Stewart (Cooke) return to his hometown for the funeral of his best friend, Callum.

Stewart left two years earlier after falling foul of his girlfriend Ellie Murston's criminal family – and they aren't exactly pleased to see him back.

Mullan, who plays Ellie's father Don, admits he wouldn't want to get on the wrong side of his character. "Anyone who doesn't mind killing someone you should be wary of at least."

However, the actor, whose previous credits include Trainspotting, My Name is Joe, and Top of the Lake, as well as directing The Magdalene Sisters, doesn't think Don can be blamed for all his clan's actions. "Most criminal families are utterly dysfunctional. I don't think he's the sole reason for it though. I think in that kind of environment you collaborate into what they've become. If you're the son or wife of somebody who makes his money through threatening others and through bullying, which most of these kind of criminals do, then you're colluding in the dysfunctionality."

So, we could understand it if Stewart turned up, paid his respects, and left, especially when Don's henchman makes it clear that's exactly what the Murstons expect. However, Stewart is puzzled by Callum's suicide, and also finds himself confronting Ellie (Spencer), the girl he left behind.

As Stewart starts digging into the circumstances surrounding his mate's death, he uncovers some of the secrets and lies that surround his hometown – and the Murston family. But he might also be falling for Ellie all over again.

Domino's Pizza: A Slice of Life (C4, 8pm)

OBSERVATIONAL documentary about life inside the fast-food company, from its UK headquarters in Milton Keynes to the dough factory where vital ingredients for its products are produced. Cameras follow a host of its employees, including a man who is hoping to be crowned Manager of the Year at an annual awards ceremony, and a branch owner who is about to open his tenth Domino's restaurant. Plus, an insight into a contest in which people compete to make a pizza in the fastest possible time.

Britain's Busiest Airport - Heathrow (ITV, 9pm)

THERE'S a reason airports are so popular with fly-on-the-wall documentary makers – they're full of human drama, whether it's joyful reunions, emotional goodbyes, or just people having meltdowns because their luggage has jetted into oblivion. As Britain's biggest airport, Heathrow has more stories than most, which this week include the staff trying to get 100,000 departing passengers on to their planes in time for take-off – and it looks like one rogue traveller may have thrown dispatcher Callie and ramp manager Steve's plans into chaos. Over at security, Sundeep search a passenger who has chosen an unusual outfit, and a royal visitor pays a flying visit.