OBISIDIO: The ILLUMINAE Files_03 is the third and final book in The Illuminae Files trilogy.
Asha Grant came to Kerenza to escape her past.
Too bad he just caught up with her.
Asha survived the initial BeiTech's assault and has been working undercover with the hopelessly outmatched resistance ever since. That, and figuring out what to do with the secret she's stashed in the crawlspace. The last thing she expected to worry about was her ex-boyfriend, but Rhys Lindstrom just landed planetside, and he's looking finer than ever in his new BeiTech uniform. Is he her way out ― or a guarantee she never gets off this frozen rock alive?
But Asha's not the only one with problems. Her cousin Kady's ragtag band of survivors are headed for Kerenza ― without enough oxygen to last the journey. Oh, and there might be an insurrection brewing. But when have little things like that ever stopped the Illuminae Group?
Too bad time isn't on their side. With BeiTech hurrying to repair their damaged jump gate, and a mass extermination planned for the Kerenza civilians, only a miracle could save them now. And everyone knows that miracles are just statistical probabilities ... right?
The novel switches between focus on Asha Grant (Kady Grant's cousin), Rhys Lindstrom (a BeiTech ground pounder), and the events transpiring on the Hypatia. On Kerenza IV, Asha, a former pharmacy intern, works as a nurse to make up for the shortage of nurses caused by the BeiTech invasion on Kerenza IV, taking care of Katya Kowalski, a little girl who she is keeping safe in her crawlspace. When her former boyfriend Rhys, now a BeiTech ground pounder, shows up on-planet as a tech specialist, Asha struggles with how to treat him. Her friend and fellow resistance member Bruno Way sees an opportunity, and persuades her to try to pull Rhys to their side before BeiTech wipes out all the remaining survivors on Kerenza IV.
Meanwhile, on the Hypatia, former Heimdall security chief Ben Garver is unsatisfied with the living conditions when he visits his godson Luke Pangburn and Luke's mother Cara who are also living on the ship, and resolves to lobby for change. But after receiving little to no response, he decides to perform a hostile takeover, in the hopes that he can make living conditions better for the survivors. In addition to that, while integrating into the Hypatia's systems, AIDAN discovers that there will not be enough oxygen to last for all the survivors until they get back to Kerenza IV, and decides, for Kady's good alone, to act against orders.