Fai, a compulsive gambler and an irresponsible man, is asked to take care of his ex-girlfriend Chik's (Anita Yuen) son, Yeung. Chik also reveals to Fai that Yeung is his son, and promises to pay him HK$100,000, so Fai agrees to be a father for one month. Soon, Fai notices his son suffers from autism and gets to understand the difficulties of raising a child with special needs. When Chik fails to show up on the date when they agreed to meet, Fai realises why she brought him his child. He finds his life goal while discovering Yeung's talent on the racing field, then decides to give up his former dissipated life and to accompany his son as he sets out to achieve his dream.