In 2008, a viral epidemic broke out in Scotland, quickly claiming many thousands of lives. To limit its spread, the authorities sealed off the country’s territory from the rest of the island with an impenetrable wall and forgot about those who remained inside. However, 27 years later, the virus has been discovered again, this time in London. Only a vaccine can stop it, for which there is only one way – to send the best soldiers to the other side of the fence and find there people who survived the epidemic.