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.