In 2026, delivery driver Chen Yuan'an accidentally connects to a landline in 1994 using a water-damaged mobile phone. To his astonishment, the person on the other end is his own father, Chen Yong, back when he was young, addicted to gambling and mixed up with gangsters. Drawing on his memories of the future, Chen Yuan'an repeatedly warns his younger father to save his wife, quit gambling, avoid danger, and start a business. Every phone call can rewrite fate, but it can also trigger new butterfly effects.