Fai used to be a Boxing champion of Hong Kong two-time, after a stint in prison for participating to a match fixing boxing, Fai is knee-deep in debt with no solution in sight. To escape his debtors, he flees to Macau and works as a gym assistant. He meets and ends up training Si-Qi, a hot-blooded young man who enrolled in an open MMA competition with no fighting experience. After a series of wins, Si-Qi is critically injured and eliminated from the tournament. Ignited by Si-Qi's persistence and unwillingness to give up in the face of defeat, he rediscovers his will to fight and steps back in the ring against the fighter who injured his student. How far will Fai's resurrected fighting spirit take his 48-year-old body?