During the Nazi occupation of a Czech city civilians are being rounded up on the slightest of pretexts and shot. One day three high school boys who crack jokes about a recently deceased "hero of the Reich" are pulled out of school by the Gestapo.
Pavel, a young student living in Prague in 1942, hides a Jewish girl in his apartment building's attic. Amidst the brutality of the occupying German army, love blossoms between the two. He is her only link to the outside world. Then the two are discovered by Pavel's mother, who forces the residents of the apartment building to decide whether Hana can remain.
In early 20th century Czechoslovakia, a gravely ill chemist recalls his discovery of a powerful explosive and how it landed in the hands of anarchists.
