Set in the UK, this terrifying tale traces the trials and travails in the life of Mark, an artist living comfortably in an apartment complex, who wakes up to find that he is imprisoned within his home without electricity, water or communication. To add to his terror, he learns that everyone else is there apart from a mysterious voice that repeatedly says, 'please remain calm, the situation is under control'.
Strange figures in Hazmat suits patrol the grounds outside and set up a military tent. Mark's neighbor, Sergei, breaks down the wall between their apartments in order to discover why they have been sealed in and try to find a way to escape. Along the way, they team up with their fellow residents, Enid, Sally and Aiden. What will the future hold in store for them?