My Sister Is Going to Kill Me: A Novel – A Whitewater Whodunnit of Murder, Secrets, and Danger on the Grand Canyon Hardcover – August 18, 2026

From the New York Times bestselling author of the runaway hit Mother-Daughter Murder Night, a Reese’s Book Club pick, comes another fun, family-centered whodunnit about two sisters who work together to find a killer as they raft down the rapids of the Grand Canyon.What's a family vacation without a little murder?Liv and Mandy Chisholm’s yearly sister trip is a sacred tradition, an attempt to bond as their lives increasingly diverge. Liv, the ever-practical older sister, packs the color-coded itineraries. Mandy, a bedazzled human tumbleweed, brings the spontaneity.This year, the sisters take off for a rafting adventure through the breathtaking depths of the Grand Canyon with a group of strangers. But beyond the terrors of whitewater rapids, sibling squabbles, and rogue reptiles, the ferocious beauty of the river carries a darker undercurrent, and an unexpected guest: a murderer in their midst.When a fellow traveler is found dead and another corpse hits the water, the rafting trip flips from idyllic sister vacation to high-stakes murder investigation. Every suspect has a secret, every clue is drenched in mystery, and Liv and Mandy can hardly trust each other, let alone their own instincts. With the river raging and danger around every bend, the Chisholm sisters must work together to catch a killer—and keep their relationship from capsizing—before it’s too late. Read more