I discovered Linda Nagata a few years ago thanks to the audiobook editions of her military science fiction trilogy, The Red, and have been hooked ever since. When she offered me a review copy of her latest release, Edges, Book 1 of her new Inverted Frontier series, I enthusiastically accepted, even if came with the slight warning that this was going to be a far different read than The Red books or her previous release, The Last Good Man.Well, Edges is, indeed, vastly different than the prior Nagata books I’ve read, but that is by no means a bad thing! Nagata trades the familiar terrain of Earth from her military sci-fi for the wide-open vastness of deep space, nifty alien tech, and an imposing threat that’s as mysterious as it is threatening.In the far future, humanity has been reduced from a vast cosmos-spanning civilization to a small pocket of survivors living in secret from a genocidal alien machine race. The Chenzeme are an autonomous fleet of robotic warships programmed with a singular mission — to wipe out newly emerged technological civilizations. Centuries after his disappearance and presumed death in an assault against Chenzeme warships, Urban returns home, and in a tamed Chenzeme warship no less, with plans to discover the lost secrets of humanity. A small crew is recruited, its mission one of scientific exploration, and they set off to explore the ruined worlds and forgotten history of their ancient ancestors, all the way back to Earth. They think the Chenzeme are the only threat out there in the realms of forgotten space. They’re wrong.As a fan of Ron Moore’s rebooted Battlestar Galactica and Alastair Reynolds’s Revelation Space series, both of which used the premise of genocidal alien machines wiping out intelligent life to great effect, the opening chapters of Edges had me hooked. Nagata establishes an interesting threat immediately, and then uses it as a launch pad to something far more philosophical and questioning. The Chenzeme, despite their propensity for violence, are rarely seen outside of Urban’s own ship. On the whole, having already extinguished so many worlds and destroyed so many lives, and given the sheer vastness of space itself, they’re largely an idle, existential threat, the boogeyman of the stars. In fact, it takes several centuries before a Chenzeme ship unaffiliated with Urban is even discovered. And, frankly, the life these intrepid explorers discover is ultimately cause for much more consternation and immediate worries.It’s the worries of long-term space travel that are really at the forefront of Edges, and Nagata takes the BSG-type threat and subverts it with some Trekian exploration and scientific wonder. Edges runs on a lot of brain power, and it’s an intellectually stimulating read that posits some truly intriguing questions and ethical dilemmas. Take, for instance, the ship’s complement of ghosts. Human life expectancy isn’t built for centuries in space, but with a combination of life-extending nano-machinery and routine storage in a cyrogenic-like pod, people are able to traverse eons in what feels like days. While their bodies are in storage, their minds are copied to digital avatars who can go through the day-to-day stuff, collecting and analyzing information, and then syncing these newly acquired memories to the host body once its awake. Sometimes, though, there’s cause for a new body to be generated, as is the case with Riffan, who wants to be a part of the Inverted Frontier journey, but can’t abandon his post and research. Solution? Send his current mind and cloned body on the journey, while he stays home and continues on with his life. The issue of branching history comes up several times over the course of Edges, as people find themselves, or at least their memories, displaced to pursue alternate paths. And what of temporary bodies that are built for situational conveniences and disposal? It’s an interesting parallel to debates on abortion, the sanctity of life, bodily autonomy, and personal agency, although one that’s not deeply explored beyond a few small conversations between Riffan and Urban. Still, it raises excellent questions and offers plenty of food for thought, and provides some very interesting meditations on cloning and the nature of individuality versus ownership.While the bulk of Edges is interested in more heady affairs and the nature of mankind’s place in the cosmos, Nagata’s proficiency in writing action beats is certainly on strong and regular display. There’s plenty of sinking “oh shit” moments as this book ramps up to its dizzying, frenetic climax and a shipful of humans fight for survival.Edges does end with a cliff-hanger, which is disappointing only because of the questions raised and the lack of immediate gratification those answers would provide. I wanted to learn more about the discoveries made and follow this crew for a little while longer. On the bright side, Nagata does tease the release of Book 2, Silver, in this volume’s conclusion, although no release date has yet been specified. In the meantime, I’ve got plenty of new and interesting things to think about, and a whole lot of speculations to be made.[Note: I received an advanced reading copy of this title from the author.]