Unforgotten review, season 4: A dollop of high-grade ITV magic

The warm, intelligent detective show masterfully straddles nihilistic noir and Midsomer twee

After Covid-related filming delays, the exceedingly likeable detective drama Unforgotten returns to ITV for a fourth six-part series. This first episode begins with a decapitated male body found spilling out of an old freezer at the dump in Haringey – quite literally a cold case, so much so that his skin has acquired the look of over-chilled meat. The only clues to this cadaver’s identity are a Marathon chocolate bar wrapper, dating the death to before the Snickers transition, and a Millwall tattoo.

DI Sunny Khan (Sanjeev Bhaskar) answers the call, for the time being without DCI Cassie Stuart (Nicola Walker). Her nerves have been worn thin by decades of dealing with the worst criminals in the land. The serial-killer rapist she and Sunny unmasked in series three had a particularly bad effect. She’s trying to take early retirement, but the HR computers are saying no. Just when she thought she was out, they pull her back in, to work the three months she needs for her pension.

You might see Unforgotten as a companion piece to the ostensibly grittier Bloodlands, which began over on BBC One on Sunday. Where that series is chilly, all broken men wailing by the side of grey loughs, Unforgotten adopts a cheerier tone. It’s not to say it doesn’t have its share of the gruesome. It’s just delivered in a slightly brighter package. Sunny, even. The chemistry between Bhaskar and Walker is vital. He’s a deadpan humourist, trying to keep spirits up in the face of violent crime. She is a schoolmarmish professional, keeping it together under tremendous stress. Both actors are terrific. I think the key is that they both smile. People are liable to smile, even murderers and policemen. Sometimes full-beam grins, sometimes rictus teeth-clinchers, but definitely smiles.

Other detective shows give their heroes “demons”. The personal issues that beset these two are merely problems, obstacles to be juggled with solving the case. It all comes together to let Unforgotten straddle nihilistic noir and Midsomer twee, an impressive balancing act in which popular appeal doesn’t come at the expense of character, warmth or intelligence. A dollop of high-grade ITV magic.

While it hangs on the leads, the supporting cast have grown into their roles, too, especially Jordan Long as Murray Boulting and Carolina Main as Fran Lingley. It has never struggled for high-profile guest stars, either. Previous series have featured Tom Courtenay, Trevor Eve, Mark Bonnar, Alex Jennings and Neil Morrissey. This time it’s Sheila Hancock, who plays the irascible, elderly Eileen, bed-bound in Cambridge. Her academic daughter Liz (Susan Lynch) is growing exasperated with her rudeness, and Liz’s fianceé would rather not invite the old girl to their wedding.

Meanwhile, there’s Ram Sidhu (Phaldut Sharma), a Southall businessman whose drinking, smoking and general widely demeanour may or may not be a sign of criminal connections. He’s probably too obvious a villain. In a third strand is Dean Barton (Andy Nyman), ostensibly a legitimate businessman, but with a surprising past. What links these people? As the writer Chris Strang said in an interview at the end of series three, “real proper evil rarely comes wearing a cloak and a dagger. It’s wearing a cardigan or a fleece.” So are the good guys.