“Fighting Edge” by Margaret Mizushima

Fighting Edge      

Margaret Mizushima
Crooked Lane Books (2026)
ISBN:  979-8892426701
Reviewed by Sandra Cruz for Reader Views (09/2026)

Deputy Mattie Walker works for the Timber Creek Sheriff’s Department alongside Robo, her 100 lb. German Shepherd K-9 companion. On an early Friday morning, she’s on a welfare check call for a single mother who failed to bring her child to the babysitter and isn’t answering her phone.

At the scene, Mattie finds the mother, Jaclyn, murdered, and her frightened toddler, Emma, crying alone in her crib. The only clue at the scene is a crack pipe left in the kitchen. Mattie contacts Jaclyn’s sister Beatrice Reynolds, who prepares to travel from Salt Lake City to take custody of Emma while the investigation gets underway.

While heading home to check on her stepdaughters Sophie and Angie, Mattie pulls over a speeding vehicle. Because the driver, Daniel Delgado, and passenger, Mateo Perez, seem nervous, Mattie brings Robo in to sweep the car and the K-9 detects drugs hidden inside the spare tire. Sensing Mateo’s visible fear, Mattie suspects that Daniel’s claim that he is his nephew is a lie. Daniel is arrested and Mateo is placed under protective custody after she contacts the Colorado Bureau of Investigation’s human trafficking task force.

Meanwhile, Mattie’s husband Cole Walker, a local veterinarian, heads to Bret Beaty’s Rottweiler kennel with his assistant Tess to conduct health exams on new puppies. On their way in, Cole notices a pickup truck driving away. It’s filled with teenagers who appear to be workers but should be in school.

As Mattie and her colleagues dig deeper, these seemingly unrelated events begin to connect, revealing a far larger and more dangerous criminal operation.

It’s always unsettling when serious crimes hide beneath the peaceful surface of a small mountain community and I was curious to see how Mattie and Robo would handle this latest case. Mattie enjoys her job, and Robo is fitting in well with the department, but she struggles to balance her demanding career and her family life. 

Cole and his daughter Angie are dealing with the traumatic experience from months earlier when they were held at gunpoint. The family is attending counseling but Mattie misses an important therapy session because the investigation is just heating up. Though she feels guilty, she and Cole share a mutual understanding of their high-pressure careers. One detail that caught my attention came in the second chapter. After reading about how Mattie trained Robo to work a crime scene, I wanted to find out more about their partnership and the important role Robo plays in the investigation.

Margaret Mizushima delivers suspense and heart in Fighting Edge, the latest installment in her Timber Creek K-9 Mystery series. Deputy Mattie Walker is once again at the center of the action and her determination and compassion make her an interesting protagonist. She’s tough and courageous, yet her emotional connection to the victims, especially Emma and Mateo, reminds readers that behind every case are real people whose lives have been shattered.  “A death in a small town created ripples throughout the community.”

Mattie’s relationship with Robo adds a deeper layer to her character, highlighting her patience and dedication to her job. Cole’s observations uncover another piece of the criminal puzzle while his presence provides a much needed balance to the darker elements of the story.

The novel explores several powerful themes, including the vulnerability of innocent people, particularly children and victims of human trafficking, and the lengths people will go to protect their loved ones.

Mizushima also examines courage and justice in the law enforcement community. Agent Rick Lawson and Dawn Gallegos of the Colorado Bureau of Investigation, along with Dawn’s Jack Russel terrier Half Pint, work with local law enforcement as the investigation into the human trafficking operation expands.

When they interview Mateo, he provides vital information about how he and others like him were lured into the system. The suspense builds as every answer leads to another question and the list of suspects grows. 

Fighting Edge: A Timber Creek K-9 Mystery by Margaret Mizushima is an exciting crime novel that combines suspense with relatable human characters. Mizushima blends investigative detail and emotional depth, creating a satisfying mystery that will appeal to longtime fans and newcomers to the series. If you enjoy crime mysteries with K-9 partners, this latest Timber Creek novel hits all the right notes.

Robo ran down into an arroyo and then scrambled back up the other side. Mattie followed, sliding down the rocky bank, racing across the sandy bottom, and then struggling to gain the top of the other side. She could hear rocks clacking and falling behind her as Del came down the first bank.