Cage fighting (aka mixed martial arts) is one of the world's fastest growing sports. It is violent, shocking and some say barbaric, but hugely popular. Inside the cage, punching, kneeing, kicking, elbowing and choking are all allowed. Whilst men have dominated the sport for years, female fights are now becoming an increasing attraction. Filmmaker Nick Holt follows the fortunes of two British female fighters as they travel to America for the biggest bouts of their lives. Both have their own reasons for stepping into the cage and both are prepared to lay their safety on the line in search of success.