On VE Day in May 1945, as peace is declared across Europe and London is celebrating, Princesses Elizabeth and Margaret are allowed to join the celebrations, against the Queen's wishes. The King, impressed by Elizabeth's pleading, asks her to report back on the people's feelings towards him and his midnight speech on the radio. Each girl, incognito, is chaperoned by a Royal Army officer with an itinerary to be back at Buckingham Palace by 1:00 a.m. Soon realizing the Queen's planned itinerary does not fulfill their expectations of fun and meeting the ordinary people, Margaret is the first to slip away from her escort, followed by Elizabeth. Both princesses are separated on two different buses and have their own night-long adventure. Margaret is befriended by a Royal Naval officer seeking to take advantage of what he believes is just an ordinary girl. Elizabeth meets and becomes acquainted with an airman who is AWOL (absent without leave). Margaret is led by her naval officer into a world of nightclubs, gambling, spiked drinks and brothels. Elizabeth and her airman have their own adventure trying to catch up with Margaret, which take them far beyond the 1:00 a.m. deadline into the early hours of the following morning.