British grandmaster Aldiss has always been a genuine innovator, straining against the boundaries of the possible, as well as a literary craftsman of high order; this British collection of 14 pieces from the mid-70's--stunning in every sense--peers deeply into the nature of imagination and the fantastic. Some entries, indeed--Aldiss calls them "enigmas," appropriately enough--are best considered as stories about stories. For a tale about a dream-researcher who persistently makes sexual advances to one of his experimental subjects, Aldiss proposes two endings: one classifies the story as imaginative mainstream, the other retrospectively propels it into the realm of science fiction. In "Enigma 2: Diagrams for Three Stories," Aldiss discusses what constitutes a story and how one is constructed, even to addressing the author's role and the limits of what it is possible for a story to do and say: a triumph of wit and substance by any standards (and rattling good stories too). Elsewhere, the fare is only slightly less exalted, yet equally surreal and probing. Three disparate people gather in a collapsing pub as the moon falls upon the Earth. Touring aliens discover the Earth sunk into Jupiter's Great Red Spot. One short piece provides a haunting preview of the Helliconia trilogy. A series of yarns set on a string of artificial planets inquire into the nature of time, sanity, free will and predestination. And still other variations fascinate while defying characterization. Brilliant, demanding, challenging, weird: for neither the fainthearted nor the faint-minded.