Nurse Hazel Almonde is caring for injured servicemen during the dark days of the siege of Malta during World War Two when she meets injured Naval Chief Petty Officer Ewan Jones, who has survived an attack on an Italian destroyer. They are immediately attracted to each other. Ewan is recruited into a naval intelligence operation to pose as an Italian naval officer who survived the sinking of the Italian destroyer. Hazel becomes his contact as the nurse attending the POW camp. Ewan infiltrates the Axis POWs to find out the invasion plans for Malta. Their relationship is severely tested when she suffers a harrowing ordeal at the hands of the Gestapo after the POW ship is captured and taken to Tripoli. Ewan escapes and finds himself in the Long Range Desert Group. Hazel is tormented again but rejoins Ewan. They return to Malta and are married, but the war continues.