Liv and Mandy Chisolm'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. Despite their differences, the connection they share has always been their anchor.
As they set out for an adventurous rafting trip through the breathtaking depths of the Grand Canyon with a group of strangers, they hope to revitalize their relationship. 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 on a hike 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. Trapped between jagged rocks and churning whitewater, the Chisholm sisters must work together to find the killer before they become the next victims.
