The first shock is that the Barbican Theatre has been reoccupied and reduced. An audience of only 400 people sits on the stage in uncomfortable seats. So much for the grand vision of the purpose-built RSC home in London. This is the start of Cheek by Jowl's three-year residency, and it looks like an admission of defeat.
The second shock is the play itself, surely one of the greatest plays about ungovernable lust and human frailty ever written, and rarely done with such clarity or purpose as in Declan Donnellan's production, which incorporates the mad scenes into the central plot to unprecedented effect.
The 17th-century melodramatic tragedy by Thomas Middleton and William Rowley is a dance of lust, sex and murder in which Beatrice-Joanna, the daughter of the Spanish governor of Alicante, employs her resentful vassal, De Flores, to kill her assigned fiancé, Piracquo.
She has fallen for a fey young bubble-haired Valencian merchant, Alsemero, whom the brilliant, open-faced and persuasive Tom Hiddleston makes the central pulse of the play.
But De Flores (Will Keen) is motivated by lust for his mistress, who hates his appearance but succumbs nonetheless. It's John Prescott/ Tracey Temple in reverse. So, to preserve her "honeymoon virginity", she endures a wedding night by proxy: one of the most extraordinary sequences in this revival is when Olivia Williams as Beatrice-Joanna beats the walls as her stand-in, the maid Diaphanta (Jennifer Kidd), groans with sexual pleasure with her husband.
The audience tumbles into this "new" floor-level arena, which Donnellan and his designer Nick Ormerod have populated with black suits, red plastic chairs and an ominous CCTV camera. The cast assembles, mumbling Hail Marys. They reconvene for the wedding swinging thuribles.
The main plot of sex and violence is played in semi-darkness. The sub-plot in the lunatic asylum is played in full light; this story of Antonio (Phil Cheadle) boarding the prison officer's punk wife (sulky Jodie McNee) becomes a complementary tale of misdirected lust in a parallel universe.
For the point about this play, with its world view darker than Shakespeare, is its psychological richness. It proposes the most barbaric yet totally understandable human behaviour.
Cheek by Jowl are back. I just wish the Barbican didn't look so desolate.
To 10 June (020 7638 8891)