When Danny Lynch tells his wife Ria that he has a young pregnant mistress, Ria thinks that her world has ended. Little does she know that within weeks a telephone call from America will open up a whole new world for her. Marilyn Vine, escaping from her own private demons, wants to exchange her house in Westville, New England, for a house in Dublin during a few summer weeks. Ria Lynch's big Victorian house in Tara Road is perfect. And so begins a wonderful story of unlikely loves and friendships, rivalries, jealousy and the uncovering of secrets, as the two women borrow each other's houses, neighbours and lives.