The prison world is full of mixed forces. It has always been divided equally by the underworld tycoon Drum (played by Patrick Tam) and the life-long imprisoned Scar (played by Cheung Kin-sing). However, the appearance of the new wrongfully imprisoned prisoner Mai Jiantian (played by Pak Tin-nam) has changed the peaceful prison life. Jiantian was first threatened by Scar to give up his appeal. Later, he was exposed to have a deep hatred with Drum and was bullied. In order to save his life, Jiantian had to accept the advice of his cellmate Hao Zheng (played by Cheung Jicong) and conspired to plan a sophisticated prison escape plan. In order to avoid the close supervision of Warden Deng (played by Wong Tak-bun), Hao Zheng set up a plan to lobby Drum for assistance, but was discovered by Scar and forced to join. As a result, the four people in prison had to put aside their prejudices and join forces to stage a thrilling prison escape!