On a secluded Greek island in the 1950s, an enormous abandoned mine is filled with sea water for a major international experiment in marine biology. It is intended to study natural selection and, perhaps, evolution in a new aquatic ecosystem. However, the experiment and the island are eventually abandoned.

Decades later, a sailor’s photograph of the corpse of a large shark prompts a team of biologists to visit the island. The team discovers unique environments, including an underwater brine lake. The life forms act in ways that affect the fauna on the island as well as themselves.

The new ecosystem is dangerous. How to cope with it? The biologists will need some form of interspecies communication with the sea life and even with a cat that has been stranded on the island. It’s simple in theory...