Publication Date: 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.
Each year, the Chisholm sisters trade off who picks the destination for their annual trip. This time around, they are set for a Grand Canyon rafting adventure.
Author Nina Simon mixes humor and thrills in My Sister is Going to Kill Me. While older sister Olivia is a profiler who focuses on structure, Mandy is spontaneous and has no problems bending the truth at will.
It’s not until they are about to battle the rapids that Mandy reveals her connection to the group’s wellness sponsor. Danger soon follows in a whodunnit that leaves bodies along the way.
The two sisters must investigate to determine who is behind sinister threats while navigating the challenging landscape. The rapids experience, coupled with the snake, proves to be quite vivid and best enjoyed through the pages of a book.
The ensuing drama offers a catalyst for the two sisters to develop a closer bond, which enhances the story’s impact.
My Sister is Going to Kill Me offers a ticket to an unexpected adventure where a murderer lies in wait.
I write crime stories about strong women. My first novel, Â Mother-Daughter Murder Night, about a grandma, single mom, and teenage girl who come together to solve a murder mystery, is out now.
Writing is my joy. In college, I was an electrical engineering student by day and a slam poet by night. After a brief stint at NASA, I started designing interactive exhibits and eventually became a museum director. I wrote two books of nonfiction about participatory, relevant cultural institutions. I thought of nonprofits as my “real” job and writing on the side.
Then, my mom got sick. I quit my job to help care for her, and I found myself turning to fiction–crime stories especially–as a way to escape during a hard time. My mom and I both always loved mysteries, and I decided to try to write one myself, with a detective/hero based on her. Now, my mom is doing better, and I’m gratefully spending my days writing, reading, and dreaming up new stories.
I live off-the-grid in the Santa Cruz mountains with my family.
