J T McIntosh (1925 - 2008)

J. T. McIntosh was the pseudonym used by Scottish writer and journalist James Murdoch MacGregor, under which all of his SF writing appeared (with the exception of a single story). Born in Paisley, Scotland, in 1925, he began publishing science fiction in 1950 with 'The Curfew Tolls', which appeared in John W. Campbell's Astounding Science Fiction magazine. His first novel, World Out of Mind, appeared three years later, and he continued to write novels of interest over the next decade and a half, but ceased publishing work after 1980. He died in 2008.

Three travellers find six very different worlds await their choice - if they have the courage to leave Eden...
On awakening in an idyllic tropical paradise, Rex is disoriented and possibly afflicted with amnesia. He knows his name, but the particulars are curiously missing. He spends his first week exploring, and discovers that his Eden-like paradise is surrounded by a huge unscalable wall 50 miles in circumference. Furthermore, there are six gateways at roughly equal intervals, but there is no way to climb up there and see where they go...