Tourists flock to the reef as humpback whales arrive to give birth; fire destroys a luxury yacht and a critical salvage mission is launched; and 20,000 green sea turtles arrive to nest at the biggest turtle rookery on Earth.

Spring brings an explosion of life to the reef as corals spawn, sea birds nest, and turtle hatchlings erupt over the beaches in tens of thousands. Manta rays swoop in to feed on the nutrient rich seas.

It's summer, the change of season. Animal and human residents prepare as a Category 5 cyclone threatens the coast. How will the reef respond to threats that challenge its delicate balance?