For several days now, the entire science team has been trying to pretend that nothing bad has happened: instruments are working, sensor readings are being recorded and analysed. However, the submarine is in a state of tension, quiet panic, and expectation of the worst.

Alexander sits at the porthole looking out at the unchanging depths of the dark water. The young scientist thinks about his life, about his ironic fate - to die from what he has dreamed of since childhood. Suddenly he notices something strange, as if a tail, but unlike any fish's one...