St. Louis shamus Alt Nudger (Nightlines, Buyer Beware) heads down to New Orleans--where jazz great Fat Jack McGee, clarinetist and club-owner, requires the services of a jazz-savvy private eye. The problem? Well, Fat Jack fears that the club's gifted piano-man Willy Hollister, an unstable sort, is in the process of seducing young singer Ineida Collins. . .who just happens to be the beloved daughter of a major mobster! So, supposedly to protect Fat Jack from David Collins' potential wrath, Nudger sets out to get the lowdown on the Willy/Ineida relationship--and on Willy's faintly creepy personality. Right from the start, then, this case seems less than entirely plausible. Then the improbability escalates--when Nudger's multi-city sleuthing quickly suggests that pianist Willy is a multiple psycho-killer: he falls in love, then always murders his beloved. (All his previous girlfriends have disappeared!) Why? Because, ""like a vampire,"" Willy periodically needs the pain of lost love to feed his soulful music-making. And, when Ineida disappears, it seems that she's about to become Willy's next victim. . .until Nudger realizes that maniac Willy is just a pawn in another villain's feebly contrived kidnapping scheme. Nudger remains a modestly likable hero, aging and downbeat and no superman--but this thin outing, in contrast to the intriguing Nightlines, is strained from beginning to end: too much psycho-nonsense and plot-contortion, too little exploration of the promising Nudger personality.