Venice is experiencing an unprecedented plague of jellyfish. The biologist Cécile Roche has an adventurous assumption about the deaths. Charlie Wagner's best friend has disappeared with her research ship without a trace. In Canada, researcher Anawak is getting to the bottom of whale attacks.

In crabs that have overrun coasts around the world, Dr. Cécile Roche detects the same bacterium that entered drinking water on the French coast via infected lobsters.