Boston: Houghton Mifflin Co., 1981 - 1984. First edition of each volume, a LIMITED ISSUE housed together IN PUBLISHER'S SLIPCASE. Number 262 of 500 sets, each volume SIGNED BY MAY in green ink on a tipped-in colophon page. This four-volume "Saga of the Exiles" (as it's known in the UK) was May's first fiction written for adults to be published under her own name. The narrative surrounds the adventures of a group of outcasts on a one-way trip to the Pliocene Epoch for, they hope, a utopian escape from the complexity and politics of their present-day intergalactic society (Wikipedia). The companion volume includes a glossary, descriptions of the characters, maps, a chronology, and three interviews with the author. The books are all crisp and fine in near fine to fine dust jackets with the barest wear. Slipcase shows light rubbing to corners and one edge but is otherwise fine. HER BEST-KNOWN SERIES.