Ruth Rendell's Thirteen Steps Down, ITV1

The red and black opening titles, in which a creepy house looms large, immediately tells the viewer we are in Hitchcock territory. However, Thirteen Steps Down, knowingly adapted for the small screen in two parts by Adrian Hodges, is based on Ruth Rendell’s 2005 novel of the same name. Like Hitchcock, Rendell knows there is laughter in slaughter.

The undesirable residence turns out to be St Blaise House and not the home of Anthony Perkins’ mummified mummy. The significance of its name lies in its location, location, location – Notting Hill where back-street abortionist John Reginald Christie once murdered six women in 10 Rillington Place. St Blaise, the patron saint of wool gatherers, was tortured to death with steel combs, horrifying implements not unlike Christie’s tools of trade.

Mix Cellini (Luke Treadaway), the “protected tenant” of Blaise House, is obsessed with Christie to the point that he keeps spotting the killer on the stairs. The servicer of gym equipment and bored housewives is delighted when his landlady, Gwendoline – never Gwen – Chawcer (Geraldine James, pictured right), reveals she once met “the unpleasant little man”.

Mix has two other obsessions. He is afraid of the number 13 – in a word, triskaidekaphobic – and Nerissa Nash, the “model of the moment”, whom he stalks, unaware that she is carrying a torch for Darel, the boy next-door of her childhood (a rugged narcissist well played by Sam O’Mahoney). He is not pleased when he finds out.

In the meantime Mix engineers an encounter with Nerissa at 13, her upmarket gym, where his love for the lonely clothes-horse does not stop him seducing a Polish receptionist. Unfortunately, back at Mix’s modish pad, she makes the mistake of not only criticising her Bootcamp – a vile cocktail invented by Mix and so called because it has “such a kick”  (despite his name, he is no mixologist) – but also Nerissa. Mix (egg-)flips. Cue a bloody climax involving a Maglite and Cliff Richard.

This is not the only scene where giggles compete with gagging. Interrupted by two of Gwendoline’s meddlesome friends (Gemma Jones and Anna Calder-Marshall), the corpse-carrying Mix has to scurry up and downstairs like a grand old duke of pork. Director Marek Losey emphasises his exercise in modern gothic with lovely time-lapse sequences of rushing clouds and the Westway at night plus lots of scary whooshing and groaning on the soundtrack (Gemma Jones pictured above).

What prevents all this just seeming like a load of knowing nonsense is the cast. Treadaway is utterly compelling as Mix, veering between chavvy charm and simmering aggression in an eye-blink, and the ever wonderful James creates genuine sympathy for the snobbish but genteelly desperate Gwen. It slowly becomes clear that the two have more in common than they would suppose.

What’s in a name? Mix (short for Michael) Cellini, Gwendoline Chawcer, Dr Stephen Makepeace Reeves (her lost love)? Rendell’s taste for outlandish or literary monikers increases the sense of a heightened reality. Nerissa, for example, is the name of Portia’s maid in The Merchant of Venice. Shakespeare was not above creating horrid laughter either. Part two next week – a rare instance of an ITV thriller not falling to pieces in the final act – reveals that for all its tongue-in-cheekery, Thirteen Steps Down is also a serious examination of obsession and the arbitrariness of love.