When Hannah and her boyfriend, Simon, set out to Amsterdam, they're confident that they'll make it to his sister's wedding in time. However, unbeknownst to them, their train is scheduled to divide in the middle of the night. And when it does, half of it continues the route to Amsterdam. And the other half--the one with Hannah in it--heads three hundred miles away, to Paris. Left without her belongings or hope of reuniting with Simon, Hannah has no choice but to spend the day in Paris before the next train out. Worse than being stranded in a foreign city alone? Being stuck with Léo, the handsome but infuriating Frenchman who blames Hannah for his own unwanted delay. The series of mishaps that sends them traipsing through the City of Light is only further proof that Hannah's day has gone from bad to worse. But as she takes in the glorious sights of the city--and spends more time with Léo--Hannah discovers that the unexpected detour might actually be leading her to the life she was always meant to live...