When an unnatural riptide pulls Tristan out to sea for three days then dumps him back on Coney Island, it's the start of something big. The Sea Court is claiming one of their own. Suddenly, his girlfriend drama and swimming championship seem like distant memories compare to the new fact that he's a Merman. Now he's in for a fight for his life, and those of his friends, as he competes for a throne as ancient as the gods.The Vicious Deep does what most books attempt and few accomplish, which is starting straight away with action. Readers are thrown blind straight into the mystery, straight into the waves with Tristan, and are left spluttering to try and keep up. It's rather enjoyable, going into a book when you're just as clueless as the narrator and have to piece everything together along with them.This book is mermaid YA for guys like Tera Lynn Childs' Forgive My Fins is mermaid YA geared more towards girls. Tristan has the perfect teenage male attitude. The teen guy snark is perfect, right down to the jokes and the hostility. He's tossed into a weird situation, gets a late explanation to the reason behind it, and then even more weirdness pops up. More of a dark mermaid story but not in the gothic horror sense. Instead, darker in terms of the story, it's more about life or death if you win or fail.There was so much crammed into this book, high school problems, mermaid problems, normal teen guy problems, plus the action and danger. It felt like a lot but at the same time it didn't. Maybe it dragged a little in the middle, in one or two spots, but the rest of the book had great pacing. When I was halfway through, I already felt wiped, but at the end I wanted so much more. It didn't feel like the end, and it isn't, not of the whole story. This was just the end of one part.There's always action, always danger, always confusion. The tension never let up as everything kept coming at Tristan, but he never seemed to buckle under the pressure. He took help when he needed it, maybe shouldered the weight of it more than he should've, but he never seemed to give up. I'm wholeheartedly excited for the next book in this series.