For the 19th century, the world beneath the sea was both the ultimate scientific frontier and the home of imagination and the fantastic. The animated documentary Proteus explores the 19th century's engagement with the undersea world through science, technology, painting, poetry and myth. The central figure of the film is biologist and artist Ernst Haeckel, who found in the depths of the sea an ecstatic and visionary fusion of science and art. His work profoundly influenced not only biology, but Art Nouveau and Surrealism, Sigmund Freud and D.H. Lawrence, Vladimir Lenin and Thomas Edison. Through extraordinary animation, Proteus brings Haeckel's vision to life.