The last book I read was Belly Up by Stewart Gibbs. The main characters are Teddy Fitzroy, Henry, JJ, Doc and Summer. The protagonist is Teddy Fitzroy and Summer. The antagonist is who killed Henry.  The main conflict is when some how Henry the hippo Fun jungles (the zoo) mascot goes belly up and no one knows how he died because he was healthy. So one of the worlds best vet that works at fun jungle, Doc cuts Henry open to see what caused Henry to die and he finds that someone might have murdered Henry so Teddy goes and investigates. The theme of the book is never give up. To me the best part of the book gives too much away about the book so my other favorite part pf the book is when Henry goes belly up in his exhibit and everyone at the park is kinda freaking out.