A marvellous performance by Sommer, as the Institute researcher, Ludvik, who returns to Prague after 20 years, anchors this powerful adaptation of Milan Kundera’s novel – a major film in the Czech New Wave, made a little before the Soviet tanks were to roll in to end the ‘glasnost’ of the so-called Prague Spring. The joke refers initially to the ill-advised postcard praising Trotsky the student Ludvik (known as Luis) sends to his beautiful but ‘naive and strict’ girlfriend, Margaret, an orthodox Communist Party member, which results in his expulsion from college, the party and Prague. Jires intercuts footage of Luis’ ‘whoring’ in the present with flashbacks to his ‘national service’ and subsequent three years in the mines, condemned as ‘an enemy of the Republic’. A moving, finely shot movie, which makes intelligent use of an adventurous range cinematic vocabulary – subjective camera, a documentary eye, low-key but highly expressive performances and traditional song and Stalinist-era music. It still stands up today, not only as a fascinating historical document, but a rich and affecting essay on personal disenchantment, moral betrayal and the tragedy of individuals caught in the rough tides of history.