In a poetic portrait of the life of the acera (sea slugs) living along the coast of Brittany, we watch the surprising reproductive ritual of these small molluscs. They are hermaphrodites, taking on both male and female roles during mating. Jean Painlevé films the species’ movements in their enchanting dance, transforming this documentary into a surrealist work of art. With a career spanning more than 50 years, the filmmaker stood out for the way he brought together scientific filmmaking and the vanguard, showing us animal life as it had never been seen before.