In this conclusion of the Abby Mullen Thrillers by the New York Times bestselling author of A Killer's Mind, a hostage negotiator has one last chance to stop a deadly threat from her past. When a series of suspicious fires leaves multiple victims dead in their homes, NYPD hostage negotiator Abby Mullen knows in her bones that the terrors of her childhood have returned. As a young girl, she narrowly escaped a fire set by Moses Wilcox, a fanatical cult leader who's been presumed dead for thirty years. These murders have his fingerprints all over them. Meanwhile, razor-sharp criminal profiler Zoe Bentley is investigating the arsons--but she's never seen an offender like this. Zoe needs insight from someone who understands the mind of a cult leader. Someone like Abby Mullen. As the unlikely duo teams up on the case, it's time for Abby to face the memories she's always wanted to forget: the cult that defined her childhood, the fire that killed her family, and the man who engineered it all. The race is on to catch a killer--even if it means braving the fiery wreckage of Abby's past.