Every time Nora Roberts slips into her J.D. Robb persona, it’s a signal for fans to buckle up for another white-knuckle thrill ride with the NYPD’s Lieutenant Eve Dallas. And to be sure, Delusion in Death has no shortage of thrills.

The madness, literally, begins in a bar owned by Eve’s business-mogul husband, Roarke, where the usual white-collar crowd has gathered for happy hour. Then something goes terribly wrong. For no apparent reason the patrons turn on each other, exhibiting such extreme violence that, when the dust clears 12 horrific minutes later, 80 people lie dead.

The few survivors of the carnage tell Eve they saw everything from terrifying swarms of bees to looming monsters followed by sudden overwhelming feelings of fear and rage. It sounds to Eve like they were somehow given a powerful hallucinogen. Roarke puts to rest Eve’s concern that he, as the owner of the bar, was the target, in which case the question becomes: Why would someone want to unleash such a nightmare? But more important is: Who? And Eve better figure it out fast. According to the M.E., this crazy cocktail can be served up again, anytime, anywhere—without a bartender. Because it’s airborne.…