After his cabin is destroyed, Friend is forced to take refuge in Gruner’s fortified lighthouse. There, he discovers Aneris, a female creature kept by Gruner as a servant and slave. Themes and Analysis

Friend soon discovers that at night, the island is besieged by humanoid amphibious creatures.

The film is often compared to The Shape of Water due to its interspecies elements, but it takes a much darker, more violent tone.

Set in 1914, just as World War I begins, the story follows a young nameless man (credited as "Friend") who arrives at a remote island in the South Atlantic to work as a weather observer.