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.

A man and woman possessed of telekinetic powers. She is the doctor. He is the experiment. What comes between them is a terrifying secret history that could save them or destroy them.

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.

Call it a premonition. Call it intuition. Call it anything you like, but Pennsylvania State Trooper Jerry McNeal simply thinks of it as “that feeling.” That feeling may come on without warning, so intense he can’t breathe.

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.

K-9 officer Jackson Locke’s sister has vanished—and the key to finding her lies with Amy Scout…his sister’s best friend and his old crush. But when Amy comes under attack, two things become clear: Jackson’s sister has been investigating cold cases and someone wants Amy dead. Now he must untangle the mystery between the cold cases and his sister’s disappearance while guarding Amy from an enemy willing to kill to hide the truth…

As a native of the small town of Hansonville, North Carolina,and a wilderness rescue worker, Raine Stockton knows the Smoky Mountains as well as anyone could, but she gave up her Search and Rescue work after a tragic loss. Now she reluctantly returns to active duty to help find a young child who has been kidnapped and taken deep into the forest.

Chief of police Tristan Church likes Marsville just the way it is. He has his job and his police dog, Fuzz, for company. He could have Sheriff Skylar Morgan, too, but she’s determined to keep him at arm’s length, even if the one night they shared was unforgettable. Skylar can’t deny that the connection she has with Tristan is unlike anything she’s ever felt before. She loves Marsville, but while most of the town is happy with her as Sheriff, it’s been a long, hard road proving herself.

When Devon Thompson’s car explodes at the click of her key fob, she doesn’t want to believe she was targeted on purpose. But when the next bomb is found in her apartment, she can’t ignore the fact that someone wants her dead. Trusting Captain Rhyland Finnegan with the truth isn’t easy, but soon she realizes Rhy is an honorable man who will go above and beyond to keep her safe.

As security agent Jonah Gray zeroes in on his current mission, he finds scientist Rachel Atwood in his crosshairs. Right before his foster brother died, he handed Jonah a slip of paper with the woman’s name on it and muttered the word “killed.” But the more Jonah gets to know Rachel, the more he’s uncertain if she’s a killer or a target. Rachel Atwood hopes to leave trouble behind when she takes a new research position at a cosmetics company located on Lantern Beach. But things aren’t as idyllic on the coastal island as she’d assumed.

Aggie Malone is a dedicated young cop who has spent her entire life just looking for a place to call home. She never thought she'd find it in a quaint Florida village called Dogleg Island, where almost nothing ever happens. Deputy Ryan Grady is an easygoing playboy who carries a surf board in the trunk of his patrol car and lives in the same rambling beach cottage his grandfather built 70 years ago. He grew up on Dogleg Island and can't imagine ever living anywhere else. It's always been the most peaceful place he has ever known.

When a fellow FBI agent is kidnapped and a protected witness vanishes, Leo Gallagher will stop at nothing to find them both. So when he discovers a link between the case and a single mother in Wyoming, Leo and his trusty K-9 partner rush to question Alicia Duncan. Could she be the key to locating the missing persons?

Someone's planting explosives on dams in the Twin Cities, and Bristol Bachmann and her bomb-sniffing dog must move quickly to find them before everything ends up underwater. That means relying on the dams' supervisor—an ex-boyfriend Bristol never thought she'd see again. An environmental terrorist wants the dams gone, and his bid to set the waters free has lethal consequences. When he sees Bristol and her K-9 working to stop him, he sets his sights on them. Can they evade him in a lethal game of cat and mouse and protect the cities from devastation before the clock runs out?