Around 1899–1900, Shiel conceived a loosely linked trilogy of novels which were described by David G. Hartwell in his introduction to the Gregg Press edition of "The Purple Cloud" as possibly the first future history series in science fiction. Each was linked by similar introductory frame purporting to show that the novels were visions of progressively more distant (or alternative?) futures glimpsed by a clairvoyant in a trance. Notebook I of the series had been plotted at least by 1898, but would not see print until published as "The Last Miracle" (1906). Notebook II became "The Lord of the Sea" (1901), which was recognised by contemporary readers as a critique of private ownership of land based on the theories of Henry George.