 String and Caitlin travel to a deserted island where a cure is being researched for a biological plague that was developed in Afghanistan. Unfortunately, the plague has already gotten out of control and the researchers are all dead. Complicating matters, the Russians have also dispatched a submarine to the island to attempt to recover the cure first. When String, Caitlin and the sub s crew all get exposed to the virus, they must work together to find the cure before they all go mad and either kill one another or die.