Set on the edges of Heathrow Airport, Wastwater is an elliptical triptych – a snapshot of three different couples who make a choice that will define the fallout of their future. Harry is on the point of leaving England. Frieda knows she will never see him again. Lisa and Mark are on the point of a sexual betrayal that takes them into a place darker than they ever thought possible. Sian has a terrifying deal for Jonathan. She isn’t going to take no for an answer.