Joseph Cotton is "David", a wealthy engineer travelling post war Italy when he encounters concert pianist "Manina" (Joan Fontaine). They have some time to kill before their flight back to the US, so go exploring and manage to miss their plane. Serendipity takes a hand - the plane crashes - affording them the perfect opportunity to play dead and allow their burgeoning romance to develop... All seems to be going to plan until his wife "Catherine" (Jessica Tandy) and young son "David Jr." (Robert Arthur) decide to visit Italy and call upon her friend "Maria" (Françoise Rosay) and... Fontaine is…