It's the day of the zoo's annual stocktake. As all the animals get ready to be counted, a group of tiny frogs take the opportunity to escape to Paris. Meanwhile, Jurgen has misinterpreted the stocktake - thinking the counts are scores out of ten. The four gorillas 'scored' only four in the previous stocktake, so he imposes a strict training regime to get the gorillas into shape for a higher score this year. His workout plan gets cut short however, when a rumour surfaces that the escapee amphibians may actually be deadly. Will the zoo ever be safe again?