Following a welcome break in Cyprus, HMS Queen Elizabeth heads back to sea. But after passing through the Suez Canal, it's discovered that one sailor has contracted Covid. By the time the ship enters the Indian Ocean, Covid is spreading almost out of control, with 400 sailors in isolation. With almost a third of the ship's labour force out of commission, command has to find ways of keeping the aircraft carrier operational, or the deployment could be seriously compromised or even abandoned. Most departments are forced to increase the length of their work shifts from eight to twelve hours, and tensions rise across the warship.