“It was the mystery that biologists from Darwin onwards had been longing to solve. How could we understand the ability of fish and seals to survive in the cold dark waters of the Antarctic? How could humans see inside a biotope that was sealed with layers of ice? What would the Earth look like from the sky, if we crossed the Mediterranean on the back of a goose? How did it feel to be a bee? How could we measure the speed of an insect’s wings and its heartbeat, or monitor its blood pressure and eating patterns? What was the impact of human activities, like shipping noise or subsea explosions, on mammals in the depths? How could we follow animals to places where no human could venture?”