This is the extraordinary love story of Clare and Henry who met when Clare was six and Henry was thirty-one, and were married when Clare was twenty-two and Henry thirty. Impossible, but true, because Henry suffers from a rare condition where his genetic clock periodically resets and he finds himself pulled suddenly into his past or future. This leads to an interesting situation; When Clare meets Henry 'normally', when she is twenty and he is twenty-eight, she has memories of him visiting her at various ages throughout her childhood, while he has no idea who she is. Likewise, when a time-travelling Henry meets Clare when he is thirty-six and she is six, he has memories of an eight year relationship and a six year marriage while she has never seen him before. In the face of this force they can neither prevent nor control, Henry and Clare's struggle to lead normal lives is both intensly moving and unforgettable.