Its quite easy to imagine the characters in Gaslight living in 1880s Waterloo.
The wavering gas supply in the lamps, though constantly turned up and down, gradually alerts heroine Bella (Rosamund Pike) to the unusual and sinister nocturnal behaviour of her tyrannical husband Jack Manningham, played by Andrew Woodall.
Tension mounts as Jack bullies his wife with cruel mind tricks and undermines her confidence in herself and her sanity.
The first half has its longueurs as the full moon floats above the rooftops. The servants wise Elizabeth (Rowena Cooper) and saucy young Nancy (Sally Tatum) bring another mood but it is the entrance of Kenneth Cranham as Detective Rough which brings humour and energy. He reveals the key to a previous occupier of the house and he cleverly bares Bella's worst fears about her husband. He gives her courage, admittedly with the Scotch, to confront and outface him.
By the curtain call Jack Manningham is booed and Rough cheered. But we sense that Bella, having seemed rather pallid and silvery like one of the living status performing in Covent Garden or on the South Bank, is about to start the rest of her life, freed from the twisted lies of her husband.