Loophole

The film opens with a safe-break that yields unexpectedly low gains for the robbers. Daniels (Finney) plots the bank robbery, having targeted this institution because he has discovered that the main subterranean vault, thought to be impregnable, lies within a short distance of a main sanitary sewer. Enlisting the services of a boat-dealer to supply equipment, he targets Booker (Sheen) who, as an architect, has the skill needed to pinpoint the exact location underground. Booker angrily rejects the first approach from Daniels but later, harassed by his bank manager (played by Robert Morley) and having to support a new business venture by his wife (Susannah York), he agrees on the undertaking, provided that no violence is to be used.