Milton's great poem can be enjoyed as a supernatural adventure story in the epic tradition-indeed almost as a science-fiction fantasy. An incredibly powerful supernatural figure-call him Father-lives on planet Heaven somewhere in outer space, surrounded by lesser supernatural beings, called Angels. Father begets Son asexually, and declares his intent to give him vice regal authority. Infuriated at Son's being promoted over him, the foremost Angel, L leads a third of the Angels in violent rebellion against Father and Son. At first it seems the rebels will best the loyal Angels. But Father sends in Son to defeat the rebels all by himself. He succeeds effortlessly, and packs them (now devils) all off to a dismal region of space, created by Father to be the devils' Devil's Island, called Hell. Father, having lost a third of his angels, and determined to complete L's humiliation, creates a new planet and places on it an (initially) immortal couple that he's created out of the dust on the planet's surface.
Jillisa Brittan & Richard A. Posner,
Classic Revisited: Penal Theory in Paradise Lost,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol105/iss6/2