This book was honestly the pinnacle of sci-fi, up there with Illuminae on my favourite books. Though it isn‘t hardcore sci-fi like Illuminae, it would be something like a “lost” sci-fi. The book takes place on a cavern filled planet where our characters were stranded years ago after an attack from an alien species. They must constantly fend off attacks from the “Krell” and untangle the past - before they crashed. 9.5/10 would recommend too anyone.