Molly Bennett and Nellie McDonough have been best mates for over twenty years. When times were hard, they kept their families together with love and laughter and were always there to help anyone in trouble. The Bennetts, McDonoughs and the Corkhills next door are one big happy family. Their children are grown up now: Molly is a grandma and Nellie's daughter Lily is making plans for her wedding to Archie. But before Nellie, as mother of the bride, can buy a posh new hat, the friends have a job to do. They want to reunite a mother with a son she hasn't seen for years and a grandson she didn't know she had.