When Griffin Bing's class takes a field trip to a floating zoo, they are shocked at how poorly the animals are treated-and to see that Savannah's missing pet monkey is in one of the cages. Legal means fail to get the monkey out of the zoo, so Griffin ("The Man with the Plan") and his friends try something they are really good at: a carefully planned illegal break-in. One thing that isn't planned is rescuing all the animals.