Warm weather brings tourists to the Isle of Sheppey, a flat, marshy island near the mouth of the River Thames. Each summer, they fill Sheppey's many caravan parks or flock to villages with seaside attractions geared toward old-school British tourists: pubs and penny arcades, minigolf and fish and chips.

Another kind of visitor stays all year round. Clustered in fields and marshes in eastern Sheppey are three prisons holding about 2,500 men. Giant wind turbines stand like sentries outside the lichen-clad walls of HMP Elmley, the largest of the three, where a 52-year-old prison officer named Paul Tottman worked.

On Oct. 28, a Wednesday, he returned home "very angry," said his wife, Laura. COVID-19 infections among HMP Elmley's staff and prisoners were rising, and Tottman, who was asthmatic, felt vulnerable. On Thursday, she said, the prison called to tell Tottman that he had been in contact with a coronavirus-positive person and should self-isolate. Soon, Tottman also tested positive, and was feverish and fighting for breath.