In this epic two-part finale, the Doctor comes face to face with the mysterious Missy, and an impossible choice is looming. With Cybermen on the streets of London, old friends unite against old enemies, and the Doctor takes to the air in a startling new role.

In 1939, Czech diplomat Jan Masaryk flees to the United States to escape his recent past: Germany has invaded Czechoslovakia and he is now a man with no nation; because, as the Czechoslovak ambassador in London, he failed to win the support of the British and could not avert the fall of his country and the outbreak of the World War II.

The story of Lyudmila Pavlichenko, the most successful female sniper in history.