This murky, mysterious, sexual thriller is absolutely gripping, steamy and psychotic.
Dr Yvonne Carmichael (Emily Watson), an acclaimed scientist, was the epitome it seemed of a respectable, middle class professional with a stellar career, two grown-up children and mild unassuming husband.
We first see her sitting at the head of a parliamentary select committee, proper, well spoken and utterly peaches and cream English.
As she leaves the parliamentary chamber and heads downstairs she grabs a coffee and is swiftly captivated by a seemingly disarming handsome stranger Mark Costley (Ben Chapman), a Westminster clerk he says.
Somehow he persuades her to pop down and see a special crypt in the basement.
Hot steamy sex in the gloom of the crypt against the stone wall was the beginning of an affair mostly conducted in broom closets, narrow dim alleys with none of it actually making sense.