The ABC Murders, episode 2 review: A Poirot investigation that’s far from cosy teatime viewing

John Malkovich's Poirot searches for a serial killer, and his own identity, in Sarah Phelps' classy Agatha Christie adaptation

Part two of BBC1’s new Poirot mini-series confirms Sarah Phelps as a very fine adaptor of Agatha Christie: like her previous Christmastime offerings And Then There Were None and The Witness for the Prosecution, The ABC Murders is developing into a moody thriller that’s far from cosy teatime viewing.

While the first episode plunged us into a rather murky 1933 – all grotty boarding houses, pea-soup fogs and nicotine-stained interiors – this time, there’s foul play afoot in the more genteel setting of Churston, a country house. There, the ABC murderer continues his alphabetical killing spree, bumping off Sir Carmichael Clarke with a garden spade. Hercule (as he's called here) is upset when he arrives too late to stop the crime, the serial killer leaving his customary page of an ABC railway guide as a bloodstained calling card. John Malkovich gives an understated performance, which pays dividends in revitalising this well-known role: his Poirot may still be prim, but at the end of a fading career, he also exhibits plenty of human frailty.

He's not the only one. The first episode hinted at the kink of our presumed murderer, a stockings salesman named Alexander Bonaparte Cust, which is now revealed: he has his landlady’s poor pimped-out daughter blindfold him with some of his merchandise, and walk across his back – already covered in weepy red wounds – in a pair of nail-studded scarlet heels. The pain is, he explains, the only thing that will “let out the darkness”. Apart from murdering people, perhaps.

Eamon Farren is perfectly cast at Cust: the camera lingers on that beautifully weird face, a cross between Cillian Murphy and one of Avatar’s Na’vi in its alien planes and piercing stare. And he’s shaping up to be a fascinating villain, full of strange compulsions and revulsions. A scene in which Cust stares at a huge yellow boil on a man’s neck before cutting into a runny yellow yolk is queasy in the extreme, and best avoided if you’ve recently overdone the eggnog.

Alex Gabassi’s direction is very good at these sorts of uneasy visual rhymes, and he’s generally fond of a portentous close-up, be that the seam of a stocking, an overflowing coffee cup or – brrr – a ventriloquist dummy’s eyeball. Add a thrumming electronic soundtrack, and the sickly yellowish-green colour pallet, and you have a drama that really goes to work on all the senses.

Phelps’s script also needles away at Hercule’s backstory: there are more flashbacks to his village in Belgium being invaded by soldiers and to him arriving in Britain in 1914 as a refugee. Questions over whether he was even a real police man, as mooted by Rupert Grint’s hangdog Inspector Crome in episode one, remain unresolved – but now, Hercule is doing the doubting himself, questioning his crime-fighting talents, and even his faith in god. As it becomes clear that the murders aren’t just following the ABC, but also relate to places Hercule himself has some connection with, the moustachioed one slips into an existential crisis.

And the ABC murderer really knows how to get to him, leaving a carefully placed note that asks “Who are you Hercule? Who are you really?” Hopefully the third part of this macabre adaptation – airing tomorrow night – will provide the answers.