When the shadowy circumstances of a relative's death are brought to light, Jane and Lila are plunged into the recesses of an underground drug operation with links to a burgeoning fascist movement. The Pool sisters have gone into business together: a down-home if unequal P.I. enterprise. That is, until Lila is tipped off to an explosive piece of news. An old friend of their Aunt Ruth's--a lawyer and academic who'd committed suicide years ago--believes that Ruth was murdered. Prior to her death, Ruth had represented a chemist who'd been struggling to patent a dangerous synthetic opioid. But once the client, Travis Nutt, was poised to lose, he went rogue and unleashed the adulterant as a street drug with the power of cartel funding behind him. Can the twins now bring this cult-like billionaire to justice?

Meanwhile, the rest of the Pool family is staying busy. Jane, newly divorced, and doing things for herself for a change, has been invited to attend a writers conference. Teenaged Chloe becomes the victim of a deepfake campaign, and secretly pursues her own aggressors. And old Harry has stumbled on a piece of unknown history that opens a door in his personal life.

Buzz Kill is a high-octane, juiced up, elastically braided narrative of a ride that shows Lennon is at the height of his powers.