Lillian Heldreth, Marleen Barr, Veronica Hollinger, and Sara LeFanu have written cogently and powerfully of the themes that inform James Tiptree's short stories, especially of the bleak vision at the heart of those many and ubiquitously violent tales that deal specifically with gender issues. And in the context especially of sexual politics, Hollinger's comment echoes what all these critics conclude, that "Tiptree's stories are modern tragedies of gender difference. At once ironically understated and parodically hyperbolic, they provide us with some of the saddest moments in science fiction" ("Defamiliarization" 202). These stories to which the preceding writers refer, the majority of which appeared between 1970 and 1977, John Clute asserts, "comprise the finest and most moving single spate of creative energy the field has ever seen" (Intro, Her Smoke Rise Up Forever x). To Up the Walls of the World (1978), on the other hand, Clute offers qualified praise, pointing out that the novel "is a complex and ambitious book--so complex and ambitious that it almost fails to work" (Illustrated Encyclopedia 183). Panning the novel in his review, Richard Cowper labels Tiptree's effort "an overlong tissue of sf cliches" (75). In this always sticky matter of worth, however, I side rather with Graham Sleight's conclusion that the award-nominated Up The Walls of the World remains "underrated" (22), some reasons for which this analysis seeks to suggest. This "complex and ambitious book" concludes in what might be described as an upbeat fashion. The tragic conflicts with which the short stories contend, however, also dominate this longer narrative, which provides no rigorously articulated resolution on a societal level to the serious issues raised, accounting perhaps, for what strikes some as the reason Tiptree's novel "almost fails to work." Veronica Hollinger, for example, views Up the Walls of the World as somewhat disappointing in that the novel "provides what is ultimately an unsatisfactory resolution to the dilemmas of its fictionalized reality" ("Grisly Truth" 125). Indeed, nearly all critics, including Sheldon herself (James Tiptree, Jr.'s actual name is Alice Sheldon), view this novel and the later Brightness Falls From the Air as less successful than her many award-winning and less-lengthy accomplishments. But the business of this complex narrative is not so much to offer solutions as to reveal currents that prevail in the world from which the narrative springs and to which, as I contend, it continues to respond.