Under the Net begins with protagonist James "Jake" Donahue returning to England to find his friend and almost constant companion Peter "Finn" O'Finney waiting to tell him the sad news that the two of them have been asked by Jake's current girlfriend, Magdalen "Madge" Casement, to leave their apartment. The two men have been living there for free. Madge has found a new boyfriend, Samuel "Sacred Sammy" Starfield, who has promised to make her famous.