The Responder review: Martin Freeman takes you on a tension-filled ride into darkness as the terrific cop drama returns

For the BBC, it seems, terrific police dramas are like buses – you wait ages for one, then Blue Lights and The Responder (BBC1, Sun, 9pm) come along at once.

We've had to wait a little longer for the second series of the Liverpool-set, Martin Freeman-starring swearathon, but on the evidence of Sunday's first episode, it was worth the two-year wait.

The first series of The Responder saw Freeman's Chris Carson – a copper balanced precariously on the edge – get entangled with his childhood friend, drug dealer Carl Sweeney.

Chris, demoted from inspector, cuckolded by a man with a personal vendetta, traumatised both by his upbringing and by what he has seen in the course of his job, is cursed by the desire to do good – a desire which always seems to take him in the wrong direction.

As we start this second series, Chris has separated from his wife, Kate – now living with his nemesis, Ray (Warren Brown) – and facing the prospect of Kate (MyAnna Buring) and his daughter moving to London.

Desperate attempts to get off the night shift are leading nowhere - “Everyone thinks you're a k***head, you know that,” his boss says – so when colleague Debs Barnes asks him for a favour in return for a 'day job', Chris finds it hard to resist.

The Responder is basically the TV equivalent of an Anadin headache – it makes you tense and nervous.

Carson is permanently in a state of nervous exhaustion, evident in everything he does as Freeman even walks as if he's in the grip of a migraine – neck pulled in, feet going 19 to the dozen, arms stiff – and every phone call he makes is spat down the line, littered with expletives.

Unfortunately, he's passed this tension on to trainee copper Rachel (Adelayo Adedayo), whose traumas from the first series are clearly unresolved, and she gets dragged into Chris's messes.

And this is not the Liverpool of the Three Graces, designer shops in Liverpool 1, or the revitalised Ropewalks.

This is the Liverpool of back alleys in Tuebrook, canal towpaths in Orrell Park and Hunt's Cross industrial estates, where the new apartments in One Park West and the boutique hotels and fancy restaurants on Hope Street – glimpsed bathed in blue light as Chris's patrol car speeds past – may as well be as far as away as Belgravia or Park Lane.

That's not to say that The Responder is depressing. The grit is leavened by a nice line in humour.

Casey and Marco, the would-be drug dealers from the first series, are back on the scene, ducking and diving in an effort to earn a quid here or there.

Their quest for easy money takes them to Sweeney's widow Jodie, who has taken over her late husband's drugs business, a fact lost on Casey until she spots a family photo on the wall of Jodie's house.

“She's Carl Sweeney's missus? I robbed his drugs,” she whispers to Marco.

“It's all right, he's dead.”

“I kicked it off though, I'm the reason he's dead.”

“Just don't tell her,” is Marco's sage advice.

But it's Freeman who dominates The Responder – his face is often the only thing we see, filling the screen, eyes darting, jaw clenching.

You're carried with him on his doomed mission to get out from under, a mission which only succeeds in pushing him further into trouble.

Meantime it makes clear that the police and the 'criminals' they are chasing are a cigarette paper apart, both seemingly pushed into a course of action by a conspiracy of circumstances.

All the way down the cast list, the performances are terrific, with Ian Puleston Davies – as Rachel's lazy and ineffective new partner – as reliably great as ever.

Meanwhile, the late Bernard Hill – as Chris's dad – hides decades of spite and venom beneath a mantle of loneliness and confusion.

It's quite the ride – just take a paracetamol before you get on this particular bus.