Alexi Kaye Campbell certainly keeps you guessing. Bracken Moor, co-produced by the Tricycle and Shared Experience, is perhaps the strangest, and certainly the most compelling, of his plays so far in combining a J B Priestley northern domestic scenario with a ghostly touch of The Turn of the Screw and Blithe Spirit.
The year is 1937: pit closures in Yorkshire, economic downturn, the rise of Hitler and George Orwell's The Road to Wigan Pier are all referenced as the middle-aged Averys, Geoffrey and Vanessa, with their 22 year-old son Terence, visit the gloomy Yorkshire home (designed by Tom Piper, spookily lit by Oliver Fenwick) of old friends Harold and Elizabeth Pritchard.
As they do so, Harold's chief collier (Antony Byrne) is producing a last-ditch plan to save the jobs of 140 miners at Ramshaw Drift, where the latest American machinery is due to be installed. The fate of the mine, it turns out, is dramatically linked to the death of the Pritchards' son, Edgar, ten years ago, in a disused shaft on Bracken Moor.
Terence, quiveringly well played by Joseph Timms, is both the conscience of the play - expressing the Orwellian arguments about the machines taking over, and the erosion of working class life in the community - and the spiritual touchstone of loss and tragedy.
Daniel Flynn's four-square industrialist and land-owner Harold is having none of Terence's nonsense, while Elizabeth, played with accumulating fervour and disintegrating sanity by Helen Schlesinger, is taken right back to the brink of her loss.
Kaye Campbell doesn't flinch as he boils up the melodrama and lays it on thick with a raging thunderstorm, an hysterical housemaid (Natalie Gavin) feeling resistance on the other side of a bedroom door and Terence possessed of a Biblical rant and a pantheistic passion after the fateful visit to the disused mine.
This all rather takes the shine off a happy weekend reunion, and Simon Shepherd and Sarah Woodward - he's an antiques dealer used to the loveliness in things, she's a busy socialite with "plans" for Elizabeth - register their disappointment in no uncertain terms.
But the bizarre and, literally, haunting developments take a more unexpected turn when Elizabeth is jolted into a new realisation about her marriage: her life finished when her son died; and when she looks in the mirror, only her husband's face stares back at her.
Shared Experience has made a speciality of plays where the metaphysical, and the afterlife, fuse in the historic present. While Kaye Campbell's play is palpably written to this order, its central political and social message, and the power of Polly Teale's notably well-acted production, maintains a high and satisfying level of achievement.