

Publication Date: May 5, 2026
How far would you go to rescue your child? A mother races against the clock—and finds herself on the wrong side of the law—in a desperate fight to save her teenage daughter in this pulse—pounding thriller from the author of Reese’s Book Club Pick and New York Times bestseller Wrong Place Wrong Time.
There is nothing that Simone won’t do for her daughter, Lucy. The two have always been close, and with Lucy about to leave home for university, they depart the UK for a vacation to Texas to spend some quality time together. But when Simone awakens on their first morning in the desert, Lucy is gone, missing from their rental cabin. In her place is a cell phone, and a voice on the other line issues a shocking ransom demand. Don’t tell the police. Come to this location. And be prepared to do a deal…
Though Simone’s husband urges her to bring in the authorities for help, she knows she can’t take any chances. The kidnappers might kill Lucy if she tells anyone. No mother would take that risk. Instead, that night, she drives to the isolated meet—up.
What she finds there changes everything. The mysterious kidnapper doesn’t want money. They want Simone to do something. The unthinkable.
A catastrophic chain of events is set in motion, with chilling consequences that extend beyond Simone and her family. What follows is a heart—pounding journey through the small towns and punishing deserts of remote Texas, in which Simone’s courage—and morality—is pushed to the brink as she discovers what it truly means to be a mother.
Unbearably tense, compassionately told, and full of well—crafted moral dilemmas, Caller Unknown proves once again why Gillian McAllister’s thrillers are “the best of the best” (Lisa Jewell).


How far will a mother go to free her adult kidnapped daughter? For Simone, it means performing a series of illegal tasks as part of the ransom.
Author Gillian McAllister uses the strength of a mother-daughter bond to underpin the latest thriller, Caller Unknown.
Simone travels from her London home for a getaway in Texas, only to find Lucy has disappeared overnight. Left behind is a flip phone and instructions to meet.
Rather than following her husband’s advice to call the police, Simone must complete a task that takes her into Mexico and back, kicking off a series of unfortunate events. Forced to go on the run, Simone faces a pivotal decision.
The story’s premise was good, but it got tangled up in the details. It includes different perspectives, which can lead to some confusion if readers aren’t paying close attention.
Caller Unknown focuses on a mother’s efforts to save her daughter.

Gillian McAllister is the New York Times bestselling author of Reese’s Book Club Pick Wrong Place Wrong Time, Famous Last Words, Just Another Missing Person, Everything but the Truth, The Choice, The Good Sister, The Evidence Against You, How to Disappear, and the Richard & Judy Book Club pick That Night. She graduated with an English degree before working as a lawyer. She lives in Birmingham, England, where she now writes full-time. She is also the creator and co-host of the popular Honest Authors podcast.















