Roberts Nora. Delusion in Death

It was just another after-work happy-hour bar downtown, where business professionals unwound with a few drinks...until something went terribly wrong. And after twelve minutes of chaos and violence, eighty people lay dead.
Lieutenant Eve Dallas is trying to sort out the inexplicable events. Surviving witnesses talk about seeing things — monsters and swarms of bees. They describe sudden, overwhelming feelings of fear and rage and paranoia. When forensics gives its report, the mass delusions make more sense: It appears the bar patrons were exposed to a cocktail of chemicals and illegal drugs that could drive anyone to temporary insanity — if not kill them outright.
But that doesn’t explain who would unleash such horror — or why. And if Eve can’t figure it out fast, it could happen again, anytime, anywhere. Because it’s airborne...