Despite a leaden opening and thuggishly uninteresting characters, Jessup's thriller plot here eventually exerts enough energy and suspense for a fairly lively read. ""Tonio Vega"" is the new, false name of a Vietnam vet (now a Columbia student in anthropology) who needs four million dollars to rescue his twin brother--a prisoner with a life sentence in Vietnam, where under his real name ""Tonio"" was once the greatest Army Intelligence specialist. So, equipped with his fake identity, Tonio sets out to hold for ransom the new, deluxe, 100-story, Fifth Avenue St. Cyr Tower, in which he has planted several packages of explosives before the place opened for business (a plot device nearly identical to that in John Lutz' Jericho Man, 1980, p. 1194). Tonio makes a series of threatening calls, exposing little traps he's set for the management so they'll realize that they can't possibly locate all his bombs. And for a convincing topper he nearly vaporizes a deserted Bronx apartment building. Chief of Security Murdoch admits he's stumped. Likewise top city detective Solomon. And tower-builder Spain is all too ready to pay off his tormentor. Finally, then, Tonio phones in his climactic demand: Spain must get the Governor to fix the first race on the first day of the new year at Aqueduct with odds at 30-to-1; the fix in, Tonio collects four million in unmarked bills from tri-state bookies and just escapes the police by ten seconds as he sets out to pay his brother's ransom. Disappointing work from the author of The Cincinnati Kid--but the unoriginal terrorism-plot, filled out with assorted killings, reaches an acceptable level of basic tension.