Tommy and Tuppence are two fictional detectives, recurring characters in the work of Agatha Christie. Their full names are Thomas Beresford and his wife Prudence (née Cowley). They started out their career as accidental blackmailers (in a search of adventure and money), but the detecting life soon proved more profitable and much more exciting.
Tuppence appears as a charismatic, impulsive, and intuitive person while Tommy is less imaginative and less likely to be diverted from the truth which is why they are shown to make a good team. It is in this first book The Secret Adversary
that they meet up after the World War I, and come to realise that, although they have been friends for most of their lives, they have now fallen in love with each other.
Unlike many other recurring detective characters, including the better known Christie detectives, Tommy and Tuppence aged in time with the real world, from their early twenties to their seventies. The stories and settings have a more pronounced period-specific flavour than the stories featuring the better known Christie characters.Tommy and Tuppence in Wikipedia