It is a boiling hot Boston summer. Adding to the city’s woes is a series of shocking crimes, in which wealthy men are made to watch while their wives are brutalized. A sadistic demand that ends in abduction and death.

The pattern suggests one man: serial killer Warren Hoyt, recently removed from the city’s streets. Police can only assume an acolyte is at large, a maniac basing his attacks on the twisted medical techniques of the madman he so admires. At least that’s what Detective Jane Rizzoli thinks. Forced again to confront the killer who scarred her— literally and figuratively—she is determined to finally end Hoyt’s awful influence . . . even if it means receiving more resistance from her all-male homicide squad.

But Rizzoli isn’t counting on the U.S. government’s sudden interest. Or on meeting Special Agent Gabriel Dean, who knows more than he will tell. Most of all, she isn’t counting on becoming a target herself, once Hoyt is suddenly free, joining his mysterious blood brother in a vicious vendetta. . . .