The family prepares Croc One, Steve Irwin's research ship, for a mission to release an endangered sea turtle back to the wild; Scarlett the giraffe reunites with her grandmother; Grub the wild echidna is released from the Zoo's Wildlife Hospital.
Robert wrangles Utah, a venomous 12-foot king cobra; Dr. Amber visits Tandora to care for wild koalas; back at the zoo, an old injury flares up for Bruce the brolga, a bird that has been in the Irwins' care for 26 years.
The Australia Zoo's alligator snapping turtles need a health check, and it's Robert's job to protect from their fierce bites; Terri and Bindi welcome seven new lemurs from the United States; the Rescue Unit must save possums caught in a chimney.
The Irwins travel to South Africa, where Terri helps release a wild leopard, Bindi learns from the all-female anti-poaching squad The Black Mambas and Robert attempts to photograph Africa's big five game animals.
Terri welcomes Mballa, a new cheetah cub from South Africa, to the Australia Zoo family; Robert sets out to save a stranded platypus and Bindi prepares to meet Bert the Koala Joey as he emerges from his mother's pouch for the first time.
Wes and Robert remove eggs from the nest of saltwater crocodiles Terra and Bosco in a nerve-wracking but necessary venture; Bindi tends to the training of otters Percival and Daisy; Terri makes a zoo volunteer's dream come true.
Terri attends the exam of Charlie the tiger to determine if his tumors were successfully treated; Bindi and the Small Mammal Team help develop a vaccine for Eden the Tasmanian devil; Robert discovers the true genders of the zoo's shingleback lizards.
The family makes the annual trip to the Steve Irwin Wildlife Reserve to capture, study and release wild crocodiles, a mission started by Steve and Terri that provides research vital to the protection of Australia's apex predators.