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.

When a young girl is found dead in the mountains outside Timber Creek, lifelong resident Officer Mattie Cobb and her partner, K-9 police dog Robo, are assigned to the case that has rocked the small Colorado town. With the help of Cole Walker, a local veterinarian and single father, Mattie and Robo must track down the truth before it claims another victim. But the more Mattie investigates, the more she realizes how many secrets her town holds. And the key may be Cole's daughter, who knows more than she's saying.

Eden Mercer, a determined young officer in the fog-shrouded, tight-knit town of Nightfall, Oregon, is haunted by her past in a fundamentalist cult. With her loyal K-9 partner, Shadow, by her side, she’s eager to prove herself in a department dominated by machismo. When a couple stumbles upon a woman’s body in a ritualistic burial deep within the dense, misty forests, Eden is thrust into a chilling mystery. As she delves deeper, disturbing clues and unsettling secrets tied to a local cult emerge.

It’s tough working nights with the NYPD. The crime rate is high, the hours are terrible, and forget about a personal life. So, when Officer O’Reilly and her K-9 Rolf switch over to the day shift, things look up. She’s even able to find time for a new boyfriend. But when the theft of a priceless painting from the Queens Museum leaves a fellow police officer dead, Erin and her four-legged partner find themselves dealing with dangerous criminals, sleazy art dealers, and obstructive detectives in a race to capture the killers...and just maybe bring closure to a 75-year-old crime.

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.

Meg and Hawk are part of the FBI's elite K-9 unit. Hawk can sniff out bodies anywhere - living or dead - whether it's tracking a criminal or finding a missing person. When a bomb rips apart a government building on the National Mall in Washington, D.C., it takes all of the team's extensive search-and-rescue training to locate and save the workers and visitors buried beneath the rubble.

After their last deployment, when she got shot, her fiancé, Martinez, got killed, and his bomb-sniffing dog, Elvis, got depressed, soldier Mercy Carr and Elvis were both sent home, her late lover’s last words ringing in her ears: “Take care of my partner.” On the Fourth of July weekend, when all of Northshire celebrates with fun and frolic and fireworks, the dog alerts to explosives and they find a squalling baby abandoned near a shallow grave filled with what appear to be human bones.

A head injury as a child gave Haley an extraordinary sense of smell. Her gift allows Haley and her German shepherd, Jax, to be one of the most successful search and rescue teams in the Midwest. When girls begin disappearing with tragic results in her hometown, Haley teams with the county’s new sheriff, Dane Campbell, to find the killer. Haley is drawn to the outgoing sheriff, whose daughter is emotionally damaged. As the murders test Haley’s gift and skills, she learns that sometimes a search and rescue can be about the heart, and the heart can lead the way home.

While hiking in the foothills of the Rocky Mountains, FBI Special Agent Kendra Dean and her K9 partner, Baxter, stumble upon a dead body stashed in the woods. The discovery changes both of their lives forever. Special Agent Rick Sanchez hunts a serial murderer who is targeting women on a multi-state killing spree. Kendra Dean, an agent Rick met on a joint mission six months ago, has found the most recent victim. Rick and Kendra once shared a tempting chemistry but time and miles made their spark a distant memory.

Alone in the wilds of mountainous Asia, Jett undertakes an undercover military operation. With threats all around her, alone is the last thing she should be. So, when help arrives, she's ready to get off the cliff's edge and back to civilization. But when her teammates K9 partner shows up carrying a plea for help, nothing will stop Jett from racing to the rescue. Not even a sexy Delta Force operator on a mission.

Former Special Forces operator Sergeant Crew Gatlin takes everything in stride, even the career-ending incident that separated him from the army, half a leg, and his beloved working dog, Havoc K027. Putting his life back together and lying low, he takes a job with A Breed Apart and is unexpectedly reunited with Havoc. It’s too good to be true—and the proof is in their first assignment: to work as a K-9 team for a television drama in Los Angeles.

Former Hanover County Sheriff Buck Lawson leaves the mountains of North Carolina to take a job as the police chief of the small South Georgia town of Mercy, and soon finds himself in over his head. For one thing, his predecessor has been murdered...Buck has inherited an unsolved homicide, a house that may well be haunted, and a police department that is almost certainly corrupt. It falls to Buck to free an innocent man and bring the former police chief’s killer to justice while wading through the quagmire of incompetence and dishonesty that permeates his office.