There are two reasons why a modest, silent German movie like this is still in circulation today. One is a matter of its authorship: all four of the unknown young men who wrote and directed it (Fred Zinnemann and Billy Wilder in addition to Siodmak and Ulmer) went on to have more or less distinguished careers in Hollywood. The other is a matter of style: it was one of the earliest movies to renounce stars, drama and the other paraphernalia of commercial cinema in favour of a non-professional cast and an unmomentous, everyday storyline. Amazingly, its variety of 'realism' has hardly dated at all. Most of it centres on a Sunday excursion from the bustle of Berlin to a countryside lake, where a bachelor and his married friend drift in and out of flirtations with two young women. Hardly anything happens, but the play of gazes, emotions and counterpoints becomes deeply engrossing. You end up not only learning a lot about life in 1929, but also realising how little sexual mores have changed.