Television drama loves border country: places hovering between one identity and another, defined by comings and goings, with forbidden bounty forever out of reach on the other side of the line. Near borders, things happen that shouldn’t. Let’s go, then, to the Thousand Islands archipelago, in the St Lawrence River between Ontario and New York state, where there are countless Ozark-y creeks to hide in, not much to do except get in trouble, and cold, cold water to sweep away your corpse if it all goes wrong. The Murder Line has a high old time there.

By choosing that title, ITV is perhaps trying to draw in sleuthing fans who would otherwise be watching Danish or Irish cops crack cases on BBC Four. But originally, in its native Canada, this show was called The Borderline – hilariously, the theme song was a slow, gruffly atmospheric cover version of Borderline by Madonna – and it’s more crime caper than detective drama, not so much a whodunnit as a willhegetawaywithit.

The trouble starts when police detective Henry “Hank” Roland (Stephen Amell) arrives at the scene of what we already know to be the killing of two traffickers, who got a shock when the guy they’d knocked out, bundled into the boot of their car and driven across the bridge turned out to be not just conscious, but armed. Hank finds evidence that tells him, and only him, that the absconded shooter is his old school mate Tommy (Hamza Haq).

Hank is now married to the police chief’s daughter and set to inherit the big job himself: he has tried to stop being Hank, the boxer and participant in illegal youthful schemes, and restyle himself as Henry, the family guy and senior community law enforcer. But he’s Hank, and always will be. Helping Tommy evade justice is going to nudge him into one of those spirals where at first you’re just lying to your colleagues, then you’re doctoring evidence, and before you know it there’s a holdall full of cocaine involved.

Meanwhile, in town, a headstrong young dreamer named Ruby (Katia Edith Wood) is skipping gleefully away from an irate, unpaid taxi driver and running up to the apartment of her drug dealer boyfriend, where she is utterly unfazed to find him dead, having overdosed on his own supply. By the end of the day she has roped in a new accomplice and they’ve killed a man, more or less in self-defence. Another holdall full of cocaine is involved.

Who else is knocking around near the US border? There’s Erica Ross (Tamara Podemski), a border patrol detective (as opposed to regular Canadian police) who likes to follow the rules, which makes her an outsider, and the person most likely to bring Hank down. Plus of course there’s someone from whom not one but two holdalls of cocaine have been stolen, and who would urgently like them back.

The Murder Line generally applies a light, playful tone to what could be disturbing subject matter: five people die in the first episode, none in a way that’s too upsetting, and the bit where Hank decides that the only person he can trust in a life-or-death crisis is an alcoholic veterinarian plays as farce, albeit a bloody one. Put it this way: if this were an American show, Vince Vaughn would probably be in it. As it is, it’s Canadian and harbouring a fetish for caricatured Britishness. Step forward Minnie Driver as May Ferguson, the drug lord who will, when she finds out what they’ve been up to, want to kill Ruby and probably Hank, too.

With her sharp bob, expensive wool coat and pernickety leather gloves, May is not the crime boss we were expecting. She looks more like the villain from a Disney movie about a corrupt finishing school. This is an opportunity, for an actor who could very easily have turned this sort of nonsense down, to muck about: Driver has fun with May’s accent, which roves around various regions of southern England before returning to its spiritual home, behind the bar in the Queen Vic. In one scene, May ends a frustrating encounter with her meat-headed henchman Gaz (Thomas Craig, who was once Tommy Harris in Coronation Street) by almost inaudibly muttering “Twat” as he shuffles away – a line that was surely not scripted, and is possibly a deliberate Danny Dyer homage. When Gaz, meanwhile, is asked a question to which he does not know the answer, he “ain’t got the foggiest!”.

Don’t come to The Murder Line for prestige drama. The stakes are too diluted and, as everyone gets deeper into difficulty, the coincidences flow too freely. But as a mischievous yarn, with characters made to entertain and a story that never stands still? It’s on the edge of excellent.