The wildlife action moves to the south coast of Australia as naturalist Steve Backshall and the Deadly 60 team take the plunge in the waters of the Pacific. Steve has heard that yellowfin tuna are super-fast lethal killers, but what makes them so special? He witnesses their missile-like streamlined bodies for himself and is left in no doubt as to their turbo-charged credentials when he dives with over a thousand of them. He then tests his own body's streamlined capabilities, with hilarious results. Strange alien-like giant cuttlefish also await Steve in the warm Pacific waters. It is then a short hop up the coast to try and track down perhaps one of the weirdest animals on Steve's list, the elusive duck-billed platypus.