Death to serial killer thrillers: why the gently subversive Unforgotten is the best detective drama of the decade

Are you bored of serial killers? Have you had your fill of tortured detectives with messy personal lives? Do you worry about TV drama’s unnatural obsession with sexual sadism aimed at attractive women? I am, I have and I do, and that’s why Unforgotten, ITV’s cold case thriller, currently running on Thursday nights, is such a brilliant antidote to the most depressing of TV trends.

There are many accomplished examples of the genre from the UK and across the globe - Luther, The Fall, The Bridge, Dexter, River, True Detective, Happy Valley - but all - even the justifiably lauded Happy Valley - suffer in comparison to Chris Lang’s drama, now in its second series.

Unforgotten has a placid and unfrenzied...