Actor Toby Flood, formerly of big and small screen but now seldom seen on either, arrives in Brighton with the other cast members of the Joe Orton play Lodger in the Throat. They have been on tour since September, but hopes of a West End transfer have been abandoned and they are all looking forward to the end of the run the following Saturday.

Flood is visited that night by his estranged wife, Jenny, now living with wealthy entrepreneur Roger Colborn. Jenny runs a shop in the Lanes and is worried about a strange man who is hanging around outside. Roger has dismissed her concerns but Jenny persuades Toby, for old times' sake, to do something. The next day Flood trails the man and confronts him. Derek Oswin is an unemployed loner who blames Roger Colborn for his father's death from cancer on account of dangerous practices at the now-closed plastics factory run by Roger and his late father, Sir Walter Colborn. However, Oswin is a fan of Flood's and eventually he agrees to lay off. Then, Colborn gets wind of Flood's contact with Jenny and tries to buy him off, but Flood sees only a longed-for opportunity to win Jenny back, and presses for answers to a host of questions surrounding the death of Sir Walter seven years earlier.

Before he fully understands the risks he is running, Flood finds himself entangled in the mysterious -- and dangerous - - relationship between the Oswins and the Colborns. The prospects of him surviving until the close of the play suddenly start to look far from good.