Peter and Lisa are settled in the comfort of their long-term marriage. Lisa is a successful shoe designer and Peter runs his own company. It is the night of the launch of Lisa's latest collection, and at dinner she seems evasive – and then odd. “Do you think two people can live together all their lives? Do you never wish you'd been given the chance to sleep with someone else?” she asks him. Then she is gone. Peter struggles to find answers, following a trail to Italy. There he meets Ralph, a slick charmer who is plainly Lisa's lover. But Ralph has secrets of his own.