On Oct. 14, 1981, Queen Elizabeth II stepped out of a Rolls-Royce in the New Zealand city of Dunedin to greet thousands of well-wishers in a routine royal walkabout—completely unaware that she had just survived an assassination attempt that came closer than any other to ending her life and radically altering the path of British history.

The queen, who was visiting New Zealand after a meeting of the Commonwealth leaders in Melbourne, Australia, had been shot at by teenager and self-styled terrorist Christopher John Lewis. Secret documents released this week reveal how embarrassed New Zealand authorities scrambled to cover up the assassination attempt, claiming the bang that rang out over the queen’s motorcade was simply a sign falling over.

Lewis was never charged with attempted murder or treason, and allegedly went on to murder after just three years in prison.