A group of scientists, led by a Professor Ortmann, produce a living human child using scientific processes — a "homunculus." This creature is human in every way, except that he cannot experience love.

A corrupt young man somehow keeps his youthful beauty, but a special painting gradually reveals his inner ugliness to all.

Part of the artificial-creature series encompassing Der Golem (1914 and 1920), Alraune (1918, 1928, 1930) and Metropolis (1926), 'Homunculus' was the most popular serial in Germany during World War I even influencing the dress of fashionable Berlin. Foenss, a Danish star, is the perfect creature manufactured in a laboratory by Kuehne. Having discovered his origins, that he has no 'soul' and is incapable of love, he revenges himself on mankind, instigating revolutions and becoming a monstrous but beautiful tyrant, relentlessly pursued by his creator-father who seeks to rectify his mistake.