S1, E4: The troubles with Patsy have come to a head. Patsy is refusing to come in at night and she's not letting any of the other elephants come in either. Barb Luciano, the young elephant keeper, has to solve the problem. Zoo vet, Dr. Graham Crawshaw, has been called to look at Charles the silverback gorilla. He will have to decide whether to operate on the great gorilla's tooth. He also must determine whether it is safe to anesthetize Charles, considering his weight and age.