Early 1950s British thriller starring Trevor Howard as David Somers, an ex Secret Service agent who takes on a quiet job at a country estate cataloguing butterflies. However, he is unable to keep a low profile for long: his employer's beautiful niece Sophie (Jean Simmons) is framed for a murder she did not commit & the two go on the run together, crossing the length & breadth of England in their frantic bid to keep one step ahead of both the police & the real murderer.