As its full title suggests, Blazing World is a fanciful depiction of a satirical, utopian kingdom in another world (with different stars in the sky) that can be reached via the North Pole. It is "the only known work of utopian fiction by a woman in the 17th century, as well as an example of what we now call 'proto-science fiction' — although it is also a romance, an adventure story, and even autobiography."
A young woman enters this other world, becomes the empress of a society composed of various species of talking animals, and organises an invasion back into her world complete with submarines towed by the "fish men" and the dropping of "fire stones" by the "bird men" to confound the enemies of her homeland, the Kingdom of Esfi.
The work was initially published as a companion piece to Cavendish's Observations upon Experimental Philosophy and thus functioned as an imaginative component to what was otherwise a reasoned endeavour in 17th-century science. It was reprinted in 1668. Cavendish's book inspired a notable sonnet by her husband, William Cavendish, 1st Duke of Newcastle-upon-Tyne, which celebrates her imaginative powers. The sonnet was included in her book.