Challenger Deep is often confusing, strange, and frustrating. I suspect mental illness is the same, which makes Shusterman's depiction of a teen (Caden) descending into (and then out of) mental issues sometimes brilliant. Some chapters portray the hallucinations Caden experiences, while some are viewpoints from his life, which revolve around a mental hospital towards the last half of the book. This was my first Shusterman title, and I can tell why he has so many fans. He pulled off a challenging feat, giving the reader solid writing and a glimpse into a world many of us know little about.