Otto was an SS officer who died by suicide after being imprisoned as a war-criminal by American authorities. Otto's ""boy"" is his 40-year-old son Ernst, raised in America by his widowed, remarried mother--but also raised by crazy Mama to be a sexually repressed psycho-racist, determined to avenge the death of his father, the ""SS martyr."" So now, as a US Army career-man, Ernst has managed to steal several canisters of vile nerve gas from an Army base--faking his own death in the murder-robbery, eliminating his accomplices, and then gleefully killing 117 people (mostly black) on a N.Y. subway as his first terrorist/blackmail-attack. Soon, of course, the NYPD unleashes its best man--super-cop David Bloom--on the case; Bloom's efforts to identify the mysterious ""O.B."" (the signature on Ernst's threatening letters) are hampered by the fact that the US Army is trying, for political reasons, to keep all info on the nerve-gas theft absolutely secret. Still, eventually, with help from a gorgeous psychiatric expert (Bloom's new love, naturally), the super-cop starts figuring out who ""O.B."" really is--though not in time to keep Ernst, whose $5 million ransom demand hasn't been met, from nerve-gassing 252 people in a movie-house. And finally, as Bloom & Co. close in on Ernst, tracking down his old crazy mother in Florida, the psycho-killer is still vowing to fill Madison Square Garden with bis super-poison. . . while the stadium is filled with more than 19,000 people. Except for the luridly detailed use of the foulest of weapons: routine psycho-terror suspense from the author of Time of Reckoning and Viper Three--with cartoon characters, predictable plotting, and crude exploitation-violence.