In 2020, a coup in Myanmar shut down the country. Gao Gao, unable to attend 　　school, spent his days with friends in the village, going through life as if nothing 　　had changed despite the unrest around him.

延續「人氣」劇《使徒行者2》的「臥底熱潮」，TVB製作香港電視史上首個由劇集演變成綜藝遊戲節目的《使徒行者 臥底遊戲》，與全城觀眾攜手尋找變節「黑警」！ 八名有嫌疑的警察：黃翠如、蔡思貝、陳凱琳、麥美恩、洪永城、楊潮凱、余德丞與Bob(林盛斌)共赴泰國，接受卓Sir(苗僑偉)安排的特別任務，抽絲剝繭找出線索，再投票選出可疑之人。真相會在終極War Game「廝殺」後揭盅，究竟誰是「黑警」？