With the threat of closure looming for any enclosure that is not up to scratch, the zoo's annual inspection day is serious. The animals scrub up to look their best. The penguins are polished, the baboons are buffed and the tigers are tidied.

A mystery illness leaves Topaz the kangaroo without a hop and the vets scratching their heads. When Topaz is taken for treatment, rumours begin to spread around the zoo that it could be a condition that causes kangaroos to lose their ability to hop.

Mysterious monsters are rumoured to be lurking in Flamingo Lagoon and keeper Pete Smallbones is on a mission to prove to the zoo that the monsters are real. The keepers and animals all think that Pete is making it up, until Sid the seagull mysteriously disappears. Could Pete be telling the truth? Meanwhile, over on gorilla island, Jurgen and the boys are having to deal with an invasion of their own as Komodo rabbits and strangen rodents start appearing in their enclosure.