It could be lights out for British sleuth Patrick Dawlish when a dangerous new drug hits London and falls into the hands of a criminal mastermind.

After a Paris vacation with his wife, Patrick Dawlish steps off the train and is welcomed home by trouble, to no one's surprise. An esteemed medical researcher who wanted Dawlish's help while being blackmailed has gone missing. For months the poor doctor's mind has been wracked with fear, derailing his work on a cure for a devastating virus and plunging him into financial ruin.

The search for the doctor puts a target on Dawlish's back—and everyone close to him—just as a series of bizarre murders begin. Some small-time crooks are drugged into a blissful sleep never to awaken again. And that's enough to convince Dawlish that there's a big-time thief behind the scenes, one who's gotten his hands on the ultimate weapon to satisfy his lust for wealth and power . . .