The fourth entry in this “compelling, passionate, and gritty” (Daily Mail, London) series by internationally acclaimed bestselling author Colleen McCullough sends Carmine Delmonico on a heart-pounding ride through the world of toxic substances and brilliant biochemists to pursue a mysterious killer on the loose.

Holloman, Connecticut, 1969. A deadly neurotoxin extracted from a blowfish disappears from a laboratory at Chubb University, and biochemist Millie Hunter knows the danger is immediate. The poison kills within minutes, leaving almost no trace behind. But before authorities can contain the threat, a prominent guest at an elegant black-tie dinner collapses and dies in agony—murdered by the stolen toxin.

As more victims follow, Captain Carmine Delmonico is drawn into a chilling investigation that cuts through the heart of the university town and its influential residents. The only apparent connection between the deaths is the presence of Dr. Jim Hunter, Millie’s brilliant husband, whose groundbreaking scientific career has already made him the target of scrutiny and prejudice as a Black man married to a white woman in mid-century America.

With suspicion mounting and tensions rising, Carmine and his detectives must untangle a web of secrets, rivalries, and old resentments hidden beneath Holloman’s polished surface. As the killer grows bolder, the investigation leads ever closer to home—and to a truth far more dangerous than anyone expected.