In medieval England, Merlin and King Arthur banish the evil enchantress Morgana and her son Mordred to the ends of the universe as Morgana vows revenge. In present day, Knights descendant Penn doesn't take much stock in the legends of his supposed ancestors, even as the descendants meet in Thailand to practice fighting. But when Morgana and her son return to earth, armed with alien technology and hell-bent on destroying every last descendant of King Arthur and his knights, Penn must to come to terms with who he was born to be, and bring together the new Knights of the Round Table to save themselves and the earth from Morgana's total vengeance.

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.

Ten years ago, Jake Hopper was a CIA agent who was stationed in Thailand. Then one day, things went sour, and his partner, Sunti barely escaped with his life...after accidentally killing a woman. Jake called it quits and returned to the United States when his wife died, and Sunti became a Buddhist monk to atone for his sins. For the past 10 years, Jake has run a successful private security business, and has been raising his daughter Jessica, who is now an adult. While hiking in Thailand, Jessica and her friend Sarah Winthorpe are kidnapped. A group of Islamic fundamentalists known as the Abu Karaf claims responsibility. Sarah is the daughter of United States senator John Winthorpe. For ransom, the Abu Karaf demand the release of 20 prisoners from American custody. The US Secretary of State urges restraint -- he won't negotiate. Tom Collins, an ex-colleague of Jake's, recognizes Jessica on the ransom tape and tips Jake off...