The Sinner, Series 2, BBC Four review - a white-knuckle ride into spiritual darkness

The first series of The Sinner in 2017 starred Jessica Biel as a disturbed woman who seemingly inexplicably stabbed a man to death on a beach, then could remember nothing about the crime.

This second season on BBC Four finds Biel on board as executive producer, but this time the story is of a young boy who seemingly inexplicably poisons a couple, and admits to doing it.

The common thread is detective Harry Ambrose, who’s called in to help out on the new case by Heather Novack (Natalie Paul), the daughter of Harry’s old police buddy Jack Novack (Tracy Letts). Last time around we saw Harry dragged through a sinister undergrowth of sexual exploitation, perverted religiosity, drug trafficking and kidnapping, and now it looks as though he might have some kind of death cult to deal with.

The story so far: young Julian Walker (Elisha Henig) is on a road trip to Niagara Falls with a couple who seem to be his parents. Their car breaks down, they have to spend the night in a motel, and in the morning Julian brings tea to the couple. They collapse in ghastly convulsions and die. When Heather, newly appointed as a detective in the small town of Keller, is assigned to the case, she’s alarmed by what she finds and asks Harry to lend a hand.

We know from last time that Harry’s personal life is a mess in various respects, but Bill Pullman plays him with a quiet, damaged empathy which makes him compellingly watchable. It also makes it seem perfectly natural that witnesses or murder suspects would find themselves opening up to Harry when they wouldn’t talk to anyone else. In addition, Harry is pretty smart behind his rumpled exterior, and it doesn’t take him long to find the jimson weed growing behind the motel kitchen which Julian used to poison his victims.

But why did the kid do it? Clearly, he’s a little strange, and haunted by frightening visions of a cowled figure which advances spectrally towards him. When Heather first questions him he subsides into a spasm of gibbering terror which could be mistaken for demonic possession. The game changes, though, when a woman called Vera Walker (Carrie Coon, pictured above with Henig) turns up at the police station, demanding angrily to see her son. It transpires that the poison victims weren’t Julian’s parents after all, but colleagues (if that’s the word) of Vera at a commune out in the boondocks called Mosswood. This place has a reputation locally as a bad karma hotspot, and the police chief has a policy of staying away from it whenever possible. The whole area, densely wooded and thinly populated, gives off an air of foreboding. “There’s something in the soil,” Harry reflects. “Things won’t stay quiet” (pictured below, Pullman with Tracy Letts as Jack).

Of course Harry persuades the chief that they need to pay Mosswood a visit, and they discover that Vera Walker runs the place (she calls it a “sanctuary community”) with the unsmiling rigidity one might associate with warders at the more austere kind of correctional institution. We know she’s been treating Julian to her own special brand of psychotherapy, and Julian tells Harry that “my mother can read minds.” Via flashbacks, we also learn that Heather Novack had a previous experience at Mosswood years earlier which she’s keeping quiet about, but which has left her disturbed and uneasy.

Evidently we’re about to be sucked into a foul-smelling swamp of dirty deeds and moral darkness. You wouldn’t call it fun exactly, but it grips like a dyspeptic alligator.

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