After Broadchurch captivated millions with its mixture of a child-murder and a picturesque coastal town where everyone seems to be hiding a secret, such places began to spring up all over the television map like moles on a golf course. That someone would want to imitate/flatter Jed Mercurio’s Line of Duty – which returns to BBC1 next Sunday after a longer than usual gap between seasons caused by the pandemic – is not surprising. It’s the most successful British crime drama of all time, basking in rave reviews and enormous viewing figures. Who wouldn’t want a piece of that kind of action?