Laureen Fortune, still foxy at forty, visits the Arecibo Observatory as guest of former lover Kelly Collins, an astronomer from the University of Chicago. The Observatory's spectacular radio/radar telescope, comprising a twenty-acre reflecting dish of exquisitely shaped aluminum sheeting, a 600-ton cat's cradle of steel girders suspended fifty stories above to hold its radio feeds, and cutting-edge radio and computing equipment, has drawn a number of other scientific investigators and hangers-on to its site in north-west Puerto Rico. Laureen knows several of these as long-ago friends and/or lovers, brought together by the Observatory's unique attractions.Laureen inhales the tortured history and mixed-up culture of the Isle of Enchantment until the idyll is broken one day by the discovery at dawn of a body that has fallen from the suspended structure, pierced the dish, and been disemboweled in the process. Finding herself and Kelly quite reasonably under suspicion of murder, she converts from pseudo-scientist to amateur crime investigator and, by her naturally contrarian processes of thought, identifies the true culprit and obtains a confession. She chooses not to reveal her solution to the investigating authorities, which, for their own reasons, would prefer not to be told.