Dive into the world of Maddie Castle, a retired K9 handler turned private investigator, in this heart-pounding collection of the first three novels in the bestselling series. From gripping mysteries to life-threatening pursuits, Maddie and her canine partners battle danger, corruption, and their own pasts to bring justice to those who need it most.

When autistic dog rehabilitator Maddie "Mad Girl" Whitney discovers a corpse on her neighbor's ranch, she impulsively tries to drum up business by claiming that psychic abilities led her to the victim . . . with devastating consequences. Maddie's forced to start a K-9 Search and Rescue team with her ex-girlfriend's twin, a hostile sheriff, or risk losing her beloved former military dog. She reluctantly begins reaching out to others . . . and finds friendship and kindness in the unlikeliest of places.

Caitlyn Reed and her dog, Renegade, are thrown into the midst of murder and intrigue when they discover a dead body while on a trail ride in the black hills of Wyoming. The local sheriff is hell-bent on a conviction, and Caitlyn’s brother, Dylan, is in his crosshairs. Desperate to prove his innocence, Caitlyn turns to Deputy Colt Branson for help, but she must grapple with their rocky romantic past to gain his aid. As Caitlyn and Renegade pursue the killer, the investigation catapults their lives in a dangerous new direction.

DEA Agent Doug Bridges is angry to realize his stepsister has been kidnapped after her night shift at the hospital. He goes into full agent mode to investigate, but soon runs into dead ends. Winter in northern Wyoming is no joke and he needs help, fast. When he’s referred to the Sullivan K-9 Search and Rescue team, he convinces Maya Sullivan and her Siberian Husky Zion to help him find Emily.

Ryder Creed and his dogs have been making national headlines. They've intercepted several major drug stashes being smuggled through Atlanta's airport. But their newfound celebrity has also garnered some unwanted attention. When Creed and one of his dogs are called in to search a commercial fishing vessel, they discover a secret compartment. But the Colombian cartel's latest shipment isn't drugs. This time, its cargo is human. To make matters worse, Creed helps one of the cartel's drug mules escape.