Plot
A car plunges over a cliff in Italy. Both passengers, newspaperman Lewis Forrester and actress Alison Ford, are killed.
In London, Lewis's brother, Tim, is a painter. He is creating a beer advertisement, using his favourite model, the comely young Jill. She and Tim have been involved, but Tim's opportunity to go further has passed: good-natured, but desiring the finer things in life, she starts a relationship with the rich Henry Carmichael. She swiftly accepts his proposal and leaves her job as a model, kissing Tim to say goodbye. A third brother, Dave, a pilot with a commercial charter service, flies to Italy to see to Lewis' remains.
Tim is visited by Inspector of Scotland Yard and questioned about his brother's death, as well as a postcard sent from Italy featuring a sketch drawn by Lewis of a hand pouring a fiasco of Chianti .
Tim receives an unusual commission from a Mr. John Smith, to paint Smith's dead daughter, Alison, the other car crash victim. Smith gives Tim a photo to work from, and a beautiful dress of hers to use in the picture. Jill visits to collect some things she had forgotten, sees the dress, and admires both it and the portrait of Alison. She leaves to meet Henry for lunch, but forgets a parcel from abroad she was carrying which she had picked up for him.
On the night Dave returns to England, he is picked up by Tim. Returning to Tim's flat, where Dave keeps a room, they discover Jill dead in Tim's bedroom, wearing the dress from the portrait. The face on the nearly finished work has been painted out and the photo on which it was based has disappeared. The police are called, as they investigate the murder, the parcel is remembered and opened. It contains an empty fiasco of Chianti, with a British label, "Nightingale & Son" – a firm which investigation reveals does not exist. This new connexion increases police suspicion that Tim is responsible for the murder.
Alison is not dead, she appears at Tim's door and explains that the woman killed in the car crash was not her; when they were driving, Lewis told her that he was on to an international diamond smuggling ring, and that her father was part of it. She angrily left the car, and assumes that Lewis must later have picked up a hitch-hiker, whose dead body was then mistaken for hers. She thinks Lewis was deliberately killed, but wants to be sure that her father did not know that the "accident" in the car was to occur.
Tim invites the police to his flat to prove that Alison is alive, but she disappears and tracks down her father, who is in a hotel. She tries to make him tell the truth about the diamond smuggling, but he is terrified, and plans to flee the country. Tim arrives as Mr Smith jumps from his window balcony attempting to commit suicide.
The postcard turns up eventually at Tim's flat. It holds the full names of all those involved in the diamond smuggling ring; including both the third brother, Lewis, and Henry Carmichael, the fiancé of Jill. After Lewis admits his guilt to Tim, they fight over the postcard. Tim wins and hands the card over to the police who work out the killer of Jill from revealing the hidden list of smugglers.
Jill had been tending to her father in hospital, who had survived his fall. She is escorted to Tim's flat by the police but not inside. As she enters the flat she finds Henry Carmichael, whom she recognises from Italy, which prompts Henry to try to strangle her to death. Tim arrives just in time to stop Henry and in the ensuing fight Henry falls through the first floor window to the street below.
In the aftermath of events, Tim and Alison are alone. He asks if she can stay with him until he completes her portrait. She asks how long this will take. When he answers "All my life", she replies "That's fine".
