After his impetuous musician girlfriend, Samantha, dies in an accident shortly after they had a fight (and nearly broke up), a grief-stricken British businessman, Ian Wyndham, living in London gets a chance to relive the day all over again, in the hope of changing the events that led up to her getting killed.

Sir Robert Chiltern is a successful Government minister, well-off and with a loving wife. All this is threatened when Mrs Cheveley appears in London with damning evidence of a past misdeed. Sir Robert turns for help to his friend Lord Goring, an apparently idle philanderer and the despair of his father. Goring knows the lady of old, and, for him, takes the whole thing pretty seriously.

A diamond advocate is attempting to steal a collection of diamonds, yet troubles arise when he realizes that he is not the only one after the diamonds.