In February 2020, Prince Charles and Camilla, Duchess of Cornwall visit the Tower to celebrate the Yeoman Warders' anniversary, the first time Prince Charles has visited the Tower in over a decade. Meanwhile, the business of researching the Tower's history goes on for Chief Curator, Tracy Borman, as she digs into the tragic story of Henry VIII's fifth wife, Catherine Howard.

As the country goes into lockdown in the midst of the coronavirus pandemic in March 2020, the Tower is forced to close its gates for the first time since the Second World War. As the weeks turn into months, cameras follow the small team of Yeoman Warders locked within the tower, keeping this great fortress running in isolation.

The tower staff prepares to reopen to paying visitors after lockdown results in the longest closure in 75 years, beginning with a special ceremonial lowering of the drawbridge. The ravenmaster makes sure his birds are ready to interact with members of the public after months in isolation, while the chief curator oversees the launch of a gruesome new attraction commemorating the executions on Tower Hill.

As the UK's lockdown relaxes in July, visitors finally return to the Tower as it reopens it gates to the public, and staff have to adjust to a new normal. The new one-way system is up and running, and new yeoman warders Barry Stringer and Darren Hardy have to get back up to speed with their historical facts.