The setting is a universe where magic is the secret of faster-than-light travel and Jump Mages are an essential part of any starship's crew. Damien Montgomery is a mid-tier mage with no family connections that finds out his special gift is about to make him one of the most wanted men in the galaxy. Having joined up with a blacklisted shipping crew, his attempts to save them from pirates results in them both surviving as well as finding themselves sheltering him against forces far beyond their control.
Damien has a sort of Shinji Ikari-esque quality of being extremely down on himself and emotionally withdrawn. Despite being in his mid-twenties, he looks like he's sixteen and doesn't have much faith in his prospects. You have to wonder what sort of treatment our protagonist got at home and at wizard's school to turn him into someone that even mage-hating human supremacists think he is too hard on himself.
Damien's anime hero-esque quality is contrasted sharply against David Rice, who is a determined merchant captain who just wants to deliver his cargo but is unwilling to abandon his Jump Mage to trumped up charges. Whereas Damien is willing to resign himself to death, David Rice is willing to upend his entire career in order to try and stay one step ahead of the law. I also liked the other members of the crew, especially the engineer Damien develops a relationship with.
This is a very easy-going story where our heroes keep getting into massive amounts of trouble but manage to punch their way out of it due to the immensely powerful amplifier that Damien turned their engine into. This isn't the kind of story where the heroes winning is ever in doubt but it's the journey rather than the destination that matters. I admitted, by the title, I expected this to be a lot more fantasy based and more akin to Spelljammer but the mages are scientifically based (or at least have the veneer of it).
The setting isn't overly complex with the Martian empire controlling most of organized space and many people resenting their power due to the near-monopoly they have on mages. We get a backstory of Eugenicists that created the mages initially and were later overthrown. It's enough to easily get the gist of everything without any confusing digressions. I also like the various wretched hives and outlaw ports we visit.
The ending is entertaining but also closes the book of what I enjoyed most about the book, which is the relationship between Damien and the merchantman crew he befriends. I won't spoil how the book ends but it seems like that plot is unlikely to continue. Still, I'm definitely going to pick up the sequels. The audiobook version is the one I recommend most to experience this series as Jeffrey Kafer does a fantastic job with his narration.