Four fighters from different backgrounds come together to train under an ex MMA rising star and then ultimately have to fight each other and the traitor in their midst.

Jake, full of anger after his father's death, is just starting to find a place for himself at his new Orlando high school - until Ryan, head of an underground MMA fight club, picks Jake out as a prime opponent. After being trounced by Ryan in front of the entire school, Jake begins training under the firm, moral guidance of a MMA master, where he learns how to fight... and how to avoid a fight. But it becomes obvious that a rematch will be inevitable if Jake wants to stop Ryan and his bullying, once and for all.

Picking up after the events of Never Back Down 2, former MMA champion Case Walker is on the comeback trail to become champion once again.

An old firm leader returns to Green Street for revenge after receiving a call that his little brother was killed, but is he able to cope with a new type of hooliganism and can he find his killer?

本部电影是《永不退缩》系列的第四部。前传中，讲述了几名普通人在家庭或者外界的影响下开启了综合格斗事业的故事。第四部中，故事将聚焦于一位女性拳击手的成长于蜕变。阿妮娅与弟弟阿斯兰二人时常参加拳击比赛，一次偶然机会，阿斯兰通过教练戴维的介绍加入了地下黑拳馆。一天，富豪朱利安出价1千英镑让阿斯兰故意输掉比赛，但阿斯兰却不顾约定将对手打趴在地。朱利安逼迫阿斯兰偿还他损失的3万多英镑。阿斯兰因态度强硬而被朱利安的保镖打倒在地，于是阿妮娅出手反击。见阿妮娅身手不错，玛莉亚希望阿妮娅能参与比赛。第一场比赛，阿妮娅与对手打斗激烈，使朱利安看得很过瘾，所以算作姐弟偿还了2万五千英镑。玛莉亚邀阿妮娅至意大利参加地下拳击比赛，结果却遭到囚禁。被囚禁的还有玛丽、瓦伦蒂娜、嘉雅等十几名女孩。很快阿妮娅便意识到自己是众多被绑架并被迫为一个致命的贩运集团而战的妇女中的一员。在面对是屈服于犯罪团伙的无理要求还是和其他受害者联合起来对抗幕后黑手的双重选择时，阿妮娅决定与玛丽、嘉雅指定详细的逃跑计划。于是在下一次的拳击比赛上，阿妮娅故意攻击玛莉亚，趁机将保镖打晕，随后又在医务室用手术刀挟持医生，让其用手机联系阿斯兰进行报警。众多女孩凭着非凡的勇气与智慧，最终警察成功赶到了地下拳馆，释放了被囚禁的女孩们，并将犯罪团伙捉拿归案。

Jailed ex-fighter Donavan Wallace strikes a deal with the prison warden for early parole - he is to go into a town to pick up a mysterious crate. He finds himself framed for the murder of a local waitress but before being thrown behind bars once again he is able to retrieve, and then hide, the crate. Donavan manages to break free from jail but finds himself pursued by various conspirators who are after the contents of the crate

A depressed ex-activist takes a job in a sweatshop where he and his coworker make a grim discovery.

A former Superkombat kickboxing champion is forced back into the ring to save his son's life.

Ryan and Shane compare asinine top 5 lists with a topical guest, inspiring surprisingly heated debate.

In this rousing sequel to Kickboxer, Tong Po broods about his defeat at the hands of Kurt Sloan. Po and his managers resort to drastic measures to goad Kurt's brother into the ring for a rematch.