The film stars Aaron Kwok, Betty Shu, Jacky Wu, Zhang Jingchu, and Collin Chou.

The film follows a group of circus performers who goes on a rampage after an accidental exposure to chemical gas left by the Japanese army in World War II, granting them superhuman abilities.

[3][4] Many years ago, somewhere in Malaysia, when the Japanese are experimenting on some gases that mutate people, their lab explodes, killing everyone inside.

One day, Sunny overhears a plan the rest of the troupe are making to explore a cave, rumored to be filled with gold.

They then try to kill Sunny, and continue opening the rest of the capsules, releasing the experimental gas which transforms them into superhuman monsters.

A few days later, Angel Chan (Chen An'er), a reporter discovers him in an obese state after Sunny wakes up from coma.

Meanwhile, several armored cars, banks and jewelry shops worth millions of dollars were blown and stolen by unidentified persons and several medical experts were abducted as well.

The attack is repelled with the help of Sun Hao and Xiuhua(the mutant couple) and one mutated member of the troupe is killed, but this exposes Sunny's weakness to cold.

Meanwhile, doctors conclude that Sunny's blood contains antibodies that kills the poison in gas but doesn't affect his mutant powers.