When Xiao Shuang (played by Juno Mak) was young, his biggest hobby was to watch "Unicron" with his father and imagine himself as a hero who defends the earth. However, when he was 8 years old, his father died in a street robbery because of protecting the police. Xiao Shuang's dream was shattered. Only his good friend, the orphan Dapeng, still believed that their "Earth Defense Team" would always exist. Because of his outstanding skills, Xiao Shuang was called by Mr. Han (played by Wang Yu)'s Matsumoto Group as a security guard and became a colleague with Da Mu (played by Lam Ka Tung) and other capable people. Xiao Shuang was assigned to be the latter's exclusive bodyguard and accompanied him every day because of his ability to protect Mr. Han's daughter Annie (played by Stephy Tang). That night, Da Mu and other old men were unwilling to let their interests be seized by Mr. Han, so they launched a rebellion. Mr. Han died and Xiao Shuang was seriously injured. Fortunately, he was rescued by a mysterious man who had been secretly protecting him for a long time. It turned out that the mysterious man was the son of the policeman protected by Xiao Shuang's father. After Da Mu took control of the company, he committed evil, so Xiao Shuang and his friends and neighbors formed the Earth Defense Team to fight against the evil!