The skilled pilot Denis Hopkins lives with his pregnant wife Valerie and has a comfortable lifestyle. When the gang of criminals headed by the sadistic Ricky Barnes breaks in his seaside house, Denis offers whatever the criminals want to protect his beloved wife but the evil Ricky kills Valerie. The baby is saved, and later the murderer is arrested and sent to the maximum security prison of Sullen Voe. Denis, moved by the purpose of avenging the death of Valerie, gives the baby and his house to his sister-in-law Christine. Then Denis breaks into a police car and is arrested, but he does not reveal his true name and is called John 'What' by the prisoners and guards. Denis attempts to escape, forcing his transfer to Sullen Voe. When he reaches the prison, Ricky sets up a confrontation, but things do not happen the way Denis expected.