Rumours are spreading around the zoo that a mystery animal is due to arrive. But who could it be? All the animals are in on the game of 'Guess Zoo' and as more and more clues are unearthed Geoffrey begins to suspect that the new arrival is a silverback to replace Jurgen. While the zoo animals continue to speculate, the keepers are busy building the new home for whoever is moving in. As the new animal arrives at the zoo gates - tensions rise... Will keepers Matt and Craig have finished the new animal's home? And will Geoffrey be proved right, are Jurgen's days numbered?

The zoo's animals love learning new tricks - Clara the seal can jump, Cheryl the cheetah can touch a ball with her nose and Duchess the elephant can hold her legs in the air. Football obsessed otters Willie and Wilby however, aren't interested in learning anything. Neither is self appointed leader Jurgen who refuses to learn any new tricks. While dedicated keeper Lee tries his best to get the otters attention, the gorillas are trying their hardest to find out why Jurgen is so against learning anything. It's all a mystery until Hank finally reveals the embarrassing 'trick' Jürgen's been hiding since he was a boy.