With King George too ill to travel, Elizabeth and Philip embark on a four-continent Commonwealth tour. Party leaders attempt to undermine Churchill.

When dense smog cripples London for days and creates a serious health hazard, Churchill’s inaction leaves him vulnerable to his political enemies.

As tensions with Philip increase, Elizabeth spends time with her old friend Porchey. Churchill’s portrait is painted for his 80th birthday.

As Philip leaves for a long tour, Elizabeth makes an upsetting discovery. Prime Minister Eden wants to strike back after Egypt seizes the Suez Canal.

Palace insiders try to prevent a scandal that could reflect poorly on Philip. Eden faces censure from his cabinet and the press.

A letter from Peter Townsend spurs Margaret to make a bold proposal. Elizabeth has good news that causes complications for Margaret.