Margaret Mizushima books in order

When a young girl is found dead in the mountains outside Timber Creek, life-long 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, local veterinarian and a 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 hometown holds. And the key may be Cole's daughter, who knows more than she's saying.

The murder was just the beginning, and if Mattie isn't careful, she and Robo could be next.

A murder investigation takes Mattie Cobb and her canine partner, Robo, into the Colorado mountains—where the brutal winter landscape conceals an equally brutal killer.

When Deputy Ken Brody's sweetheart goes missing in the mountains outside Timber Creek, Mattie Cobb and Robo are called to search. But it's mid-October and a dark snow storm is brewing over the high country—and they're already too late. By the time they find her body, the storm has broken and the snow is coming down hard.

While Brody hikes down to bring back the forensics team and veterinarian Cole Walker gathers supplies to protect them from the storm, Mattie and Robo find themselves alone, guarding the gravesite overnight in the dead of the early winter.

And that's only the first long, dark night in a series of them, because as their investigation develops, Mattie, Robo, Brody, and Cole find themselves in the middle of the killer's stalking ground—with no way out unless they can catch a predator more deadly than any natural threat.

A string of disappearances leads Mattie Cobb and her K-9 partner, Robo, into another bone-chilling investigation.

Deputy Mattie Cobb is in a dark place and has withdrawn from Cole Walker and his family to work on issues from her past. When she and her K-9 partner, Robo, get called to track a missing junior high student, they find the girl dead on Smoker’s Hill behind the high school, and Mattie must head to the Walker home to break the bad news. But that’s only the start of trouble in Timber Creek, because soon another girl goes missing—and this time it’s one of Cole’s daughters.

Knowing that each hour a child remains missing lessens the probability of finding her alive, Mattie and Robo lead the hunt while Cole and community volunteers join in to search everything—to no avail. It seems that someone has snatched all trace of the Walker girl from their midst, including her scent.

Grasping at straws, Mattie and Robo follow a phoned-in tip into the dense forest, where they hope to find a trace of the girl and rescue her alive. But when Robo does catch her scent, it leads them to information that challenges everything they thought they knew about the case.

On a rugged Colorado mountain ridge, Mattie Cobb and her police dog partner Robo make a grisly discovery--and become the targets of a ruthless killer.

Colorado's Redstone Ridge is a place of extraordinary beauty, but this rugged mountain wilderness harbors a horrifying secret. When a charred body is discovered in a shallow grave on the ridge, officer Mattie Cobb and her K-9 partner Robo are called in to spearhead the investigation. But this is no ordinary crime--and it soon becomes clear that Mattie has a close personal connection to the dead man.

Joined by local veterinarian Cole Walker, the pair scours the mountaintop for evidence and makes another gruesome discovery: the skeletonized remains of two adults and a child. And then, the unthinkable happens. Could Mattie become the next victim in the murderer's deadly game?

A deranged killer torments Mattie with a litany of dark secrets that call into question her very identity. As a towering blaze races across the ridge, Cole and Robo search desperately for her--but time is running out.

Two brutal murders, a menacing band of poachers, and a fearsome creature on the loose in the mountains plunge Mattie Cobb and her K-9 partner Robo into a sinister vortex.

An explosion outside a community dance sends Mattie Cobb and Cole Walker reeling into the night, where they discover a burning van and beside it the body of outfitter Nate Fletcher. But the explosion didn't kill Nate--it was two gunshots to the heart.

The investigation leads them to the home of rancher Doyle Redman, whose daughter is Nate's widow, and the object of one of their suspect's affection. But before they can make an arrest, they receive an emergency call from a man who's been shot in the mountains. Mattie and Robo rush to the scene, only to be confronted by the ominous growl of a wild predator.

As new players emerge on the scene, Mattie begins to understand the true danger that's enveloping Timber Creek. They journey into the cold, misty mountains to track the animal--but discover something even more deadly...

Murder stalks the rugged Colorado high country--and sends Mattie Cobb on a quest to uncover the darkest secrets from her past...

A deluge has flooded the high ground near Hanging Falls--but heavy rains aren't the only menace descending on Timber Creek. While on a scouting mission to pinpoint trail damage, officer Mattie Cobb and her K-9 partner Robo stumble upon a body floating at the edge of a lake. Robo catches human scent, which leads to an enigmatic forest-dweller who quickly becomes suspect number one.

With help from veterinarian Cole Walker, Mattie identifies the victim, and discovers an odd religious cult whose dress and manners harken back to the 19th century. As the list of suspects grows, an unexpected visit from members of Mattie's long-lost family sheds new light on her childhood as they help Mattie piece together details of the fateful night when she was abducted at age two.

The tangled threads of the investigation and family dynamics begin to intertwine--but darkness threatens to claim a new victim before Mattie and Robo can track down the killers.

A deadly secret is buried in the Colorado high country--and murder is only the beginning...

He was suspect number one--the man who tried to kill Deputy Mattie Cobb and may have killed her father thirty years earlier. But when Mattie and cold case detective Jim Hauck reach the Colorado state prison where they will finally get to interview him, he's found dead in his cell. There's only one clue: a map leading to Timber Creek and rugged Redstone Ridge.

Though she usually works with veterinarian Cole Walker, Mattie's K-9 partner Robo has just sired a litter of pups, who require special, time-consuming care at Cole's clinic. Left to explore the map's clue without him, Mattie and Robo journey into the burned forest surrounding Redstone Ridge. But before they can finish their search they're called to help investigate the death of a young woman found in a campground filled with elk hunters. Identification of the deceased points to her having recently given birth, but the infant is nowhere to be found.

As a deadly storm descends upon the mountains, covering everything with a layer of ice and snow, Mattie and her team search for the missing newborn. The storm batters the area, taking its toll on the team and forcing the sheriff to call in reinforcements. When new evidence surfaces, they decide that finding the woman's killer will lead them to her baby, making them even more desperate to solve the case.

Then Cole goes missing, stranded alone in the high country with a person that Mattie now suspects is the mastermind behind several murders, including her father's. She and Robo take to the trail to find Cole--but the killer has a cold-blooded plan that threatens them all.