Settling down for a 24-hour flight to Australia, Lucy finds a text message on her phone from a woman claiming to have slept with her boyfriend, James, four times in the past month. Trapped above the Pacific, she questions everything about their relationship, but when she finally calls him, James reassures her that it was only his friend playing a joke. James is gorgeous and successful and Lucy adores him, yet at her best friend Molly's wedding in Sydney, she finds herself having doubts and is keeping an eye on Molly's brother-in-law Nathan. Nathan is a happy-go-lucky surfer boy with no prospects, no place to live, and an almost-girlfriend in tow. Suddenly, Lucy finds herself caught between two distant continents and two very different men.