When Gary, the big cat keeper, dies and Marie, the hippo keeper, goes missing, it looks like the food chain has been reversed at Maabade Zoo. But it's not the animals out for blood, it's murder. When Nicola books a sleepover safari as Charlie's surprise birthday present — and an excuse to investigate — Charlie's obscure expertise in animal behaviour leads to a gruesome find. But now the heat is on Nicola and Charlie, literally. They're close to the truth, and it's a truth someone will kill them for.