Tom Bates is racked with guilt over causing his daughter to be an invalid (she accidentally ran into an oncoming truck after catching him and his secretary having sex), so he reluctantly invites a young man, whom he mistakenly believes is his daughter's old school friend, home to dinner. Mrs Bates finds their visitor quite charming and welcomes the change in the arduous work of taking care of their daughter, so invites him to stay for a few days. Mr Bates is leery of Martin, but in the interest of keeping peace with his wife and trying to keep his guilt in check, agrees to let him stay. Martin slowly exploits the Bates's trust as he hatches an evil plot that will change all of their lives. A typically dark, disturbing tale from the late Dennis Potter.