Linus, son of island doctor Marek, volunteers for a dangerous mission on the mainland. Meanwhile, an alarm goes off in the water treatment plant.

After returning from the mainland, a resident succumbs to the virus, whereupon island boss Beatrice looks for the culprit. Marek is researching an antidote because Linus is also infected.

Marek realizes that the lab ship Linus was talking about is their only hope. On land, Hendrik, Beatrice's outcast son, teams up with the gang boss "the Count".