The Luminous Dead

Sci-fi horror mystery where Gyre, a professional caver on a foreign planet, dives down into a strange underground cave system, monitored by Em, a woman with mysterious intentions. 
I really liked this book! The writer did a great job setting up the claustrophobic, confusing and creepy cave system.   The characters were both flawed and realistic, the tension between the two was really well rendered, each of them having their own secrets.  I also did like the sapphic angsty yearning.  The mounting tension and dread concerning the cave itself and what happened in the past was also well rendered by the author, the paranoia corrupting Gyre's mental health, like a parasite.  Some parts I struggled through, some elements felt a bit repetitive or too long, I felt like shaving some pages off could have made it more into a page turner. Also the ending felt a bit abrupt to me. 
Overall this was an incredibly solid debut novel !