During a trip to Las Vegas with his best friend, gambler Sing Wong (Jonathan Ke Quan) loses all his money. The pair learn about Ren Lee (Ekin Cheng), a man who controls a way of going back in time, from a young woman. Both his best friend and the woman die in a car accident. Sing is the sole survivor. Sing, now pursued by policewoman Tina Chow (Cecilia Cheung), is led by Ren Lee through various parallel universes and in this process he not only changes himself and saves his friend's life but also falls in love with Tina.