A team of divers, photographers, and scientists set out on a thrilling ocean adventure to document and reveal how the oceans are changing. The group follows Richard Vevers, a former ad man, who left his advertising career to become an underwater photographer. Captivated by the magic of the reefs, he sets out to share his love of the oceans with the world. He meets with the world’s most brilliant coral scientists and learns of a horrific event unfolding: an underwater heatwave is killing corals around the planet. With young scientist and self-proclaimed “coral nerd” Zackery Rago, the film team ventures to remote regions of the planet, racing the clock and battling the unpredictable nature of the ocean to document this beautiful yet haunting phenomenon.