"The Return of the Fly" is a 1959 science fiction horror film and a sequel to the original 1958 film, "The Fly". The story follows the son of the original scientist, Andre Delambre, who becomes obsessed with his father's experiments involving teleportation. He attempts to recreate the teleportation device, leading to disastrous consequences. As the plot unfolds, the son accidentally merges his DNA with that of a fly, resulting in a transformation that causes him to struggle with his new identity. The film explores themes of scientific ambition and the dangers of tampering with nature, ultimately leading to tragic outcomes.