This film took the top honor at the 1969 Berlin Film Festival. After a series of documentaries, this marks the directorial debut for Zelimir Zilnik. It takes a decidedly anti-Stalinist view in the wake of the 1968 Russian invasion of Czechoslovakia and raises important political questions. He states that although the world has experienced untold wars, there have only been a handful of revolutions with any lasting significance that lead to political change.
Troubled by bouts of sleepwalking and disturbing nightmares, graduate student Sarah Foster goes to her university sleep research center for help. But when she wakes up after her first night of being monitored, the world she lives in seems to have changed in subtle, Twilight-Zone-esque ways.