In the lead-up to The Force Awakens, one particular character caught the eyes of fans: a tall, chrome-clad stormtrooper played by Game of Thrones’ Gwendoline Christie. Captain Phasma was hyped as a silent but menacing Boba Fett-style character, but when the film came out, she only had a couple of minutes of screen time. Fortunately, Phasma, a new tie-in novel by Delilah S. Dawson, provides a much-needed origin story for one of the new Star Wars saga’s most mysterious characters.

While Phasma fills out its title character’s background a great deal, it doesn’t actually take us inside her head. Instead, Phasma’s story is told by a captured Resistance fighter named Vi Moradi, who is being interrogated by a crimson-armored stormtrooper named Cardinal a few years before the events of The Force Awakens.

From Moradi, we learn that Phasma grew up on the distant planet of Parnassos, where environmental catastrophes have sentenced its inhabitants to short, bitter lives. Then, an escape pod of stormtroopers drops out of the sky — including Brendol Hux, father of The Force Awakens antagonist General Armitage Hux. Hux is impressed by Phasma’s fighting abilities, and makes her a promise: help him back to his ship, and he’ll take her and her people off world to join the First Order.

There’s certainly a ‘Mad Max: Fury Road’ feel to Phasma’s past

Phasma and her companions jump at the chance, and end up making a brutal trek through the post-apocalyptic terrain of Parnassos, encountering enemy raiders, long-neglected droid factories, desperate settlements, and bombed-out ruins. There’s a certain Mad Max: Fury Road feel to the story, which relentlessly drives its characters from one life-threatening incident after another. Dawson slowly cranks up the heat, putting her characters into a pressure-cooker to see who survives.

Meanwhile, Cardinal and Moradi are stuck in their own game of cat and mouse. The captain is particularly interested Phasma’s backstory, trying to find damning information that will get her drummed out of the First Order, so that he can reclaim his former prestigious role as the architect behind the stormtrooper corps. At the same time, Vi is trying to stay alive, and recognizes that Cardinal has a vulnerability: while he’s a true believer in what the First Order offers the galaxy, he isn’t quite onboard with its brutal tactics, and Phasma represents a corruption in his vision for his world.

As Vi recounts her story, we learn that Phasma is an opportunist who will do anything — including sacrificing those who are close to her — to survive, and the First Order merely represents a useful place to utilize her skills. The novel gives Captain Phasma a depth that doesn’t come through in the film, and helps to explain some of her actions during The Force Awakens, like why a cold and capable warrior was so willing to cooperate with the Resistance after being captured.

But it’s the reactions of characters around Phasma that makes this an engrossing read. This isn’t so much a character journey for her as it is for those who experience or hear her story. It’s about a group of people recognizing a character that embodies raw power, and how they can use it to their own ends. Hux recognizes Phasma’s deadly potential to add to the ranks of his army, while her companion Siv tries to make sense of the true nature of the woman she idolizes, while hoping that Phasma will help lead them to a better world.

Phasma adds depth and nuance to a potentially one-dimensional evil enforcer, in a way that enhances her role on the screen as well. When The Last Jedi hits theaters in December, I’ll be watching to see if her opportunism presents itself again. Will she bail at a critical moment, if she decides that staying with the First Order no longer makes sense?