The year is 2045 and Samantha is a fourteen-year-old girl who lives with her scientist parents on an island off the coast of Georgia. The world she lives in is deep in climate crisis. Ocean levels are steadily rising, swallowing up island after island, forcing her to move several times. Coastal cities are destroyed and millions of people are displaced and left homeless. Samantha even had to live in a tent city and out of the family car for a short time. Temperatures are rising, both above the water and in the ocean, which has caused bio-engineered coral reef systems that are heat resistant to develop further north than ever before. Samantha's mother and father were recruited by the Reef Restoration project to help study the new reefs.
Samantha is obsessed with the ocean in her own way and spends a lot of time exploring the reef. She encounters an octopus one day that purposefully attempts to communicate with her and from there the story dives deep into the exploration of the species' intelligence and the quest to save the planet.
The book is written from the viewpoint of Samantha, and Charlie the octopus.
Humanity has sent the planet into a climate tailspin, but the book focuses the most on the scientific community's efforts to reverse climate change and save the environment.