Today's the big day for Charles. He is having his operation and it is a huge production. Charles is too large to move to the health centre, so they build an operating room in the gorilla house and bring in a team of medical experts to operate on the ailing gorilla. Tahra Collins is a summer worker at the zoo who wants to eventually work here full-time. Today she is learning how to catch and weigh the Tasmanian devils. At the zoo summer camp a young camper named Eric has learned the mating call of the male Indian rhino. Today he will try it out on the female rhino Indira... with surprising results.