Yin decides to reform after committing a crime. Unfortunately, his mother is diagnosed with blood cancer, so Yin attempts to steal a car with his friend for the medical fee. They hit the car owner by mistake, who happens to be the bone marrow donor for Yin's mother...阿然犯事受監管,獲安排學習維修汽車。兒子改過自新,阿然母親深感欣慰。她後來患上急性白血病,急需入院做移植骨髓的手術。阿然為了讓母親可以盡快康復,只好鋌而走險,與朋友偷竊車輛。汽車被盜,車主窮追不捨,阿然撞傷了他。車主原來是然母的骨髓捐贈者......