Three things make "Crossover" a good solid science fiction novel: an action-packed cyberpunkish plot about far future inter-stellar political and military intrigue, a willingness to explore the issues around whether an man-made soldier can also be a person and, most of all, strong female characters, especially the artificial soldier herself, Cassandra Kresnov.
Joel Shepard builds his future world with care, paying attention to history. culture, and politics and setting up conflicts that are more complex than good-guys versus bad-guys. He has created a credible, engaging universe that could be the foundation for a good series of books.
The thriller plot has some excellently executed action scenes and just enough political intrigue to vary the pace.
Yet this isn't a "Olympus Has Fallen" you have 24 hours to save the universe kind of book. It's main focus is on Cassandra Kresnov who was built to be a super-soldier but has gone AWOL to see if she can do more with her life. A lot of the novel is spent exploring what it means to be sentient but not human, to look human but to be a formidable weapon, even when unarmed. Joel Shepherd gives this debate an excellent via a gruesome scene, early in the novel, where Cassandra is treated like a thing rather than a person and subjected to unbearable cruelty. By the end of this, I had no doubt Cassandra was a person.
Cassandra is not written a human who happens to have a different biology. She is, in many ways, alien and threatening. She knows why she was built, she just doesn't believe that she has to be bound by her maker's intent. We see her as "Captain Kresnov" commanding a crew of super-soldiers, slightly less advanced than her, who she cares for and who virtually worship her. We see her as the wannabe civilian, looking for a job, going to art galleries, picking up a man, trying to build a life. we watch her build trust, suffer grief, be overwhelmed by anger and crippled by fear. We are given every opportunity to like her. The humans she interacts with are more than foils or plot devices, the SWAT squad leader and the President of the planet are drawn with precise, confident strokes that make them easy to imagine.
I found the start of the book a little slow but I suspect this was more to do with how the book was narrated. Later in the book, Dina Pearlman does an excellent job with both the dialogue (wonderful accents and distinct voices for the main characters) and with action scenes, but her reading of the early scene-setting descriptions and some of Kesnov's internal reflections is a little flat and unsympathetic. I also thought the last chapter of the book could have been omitted or given more bite.
But these are small complaints. This was a book I read with pleasure, wanting to know what happened next, caring about the characters and kept interested in the diversity of the world in which the action takes place.