Deputy Mattie Cole and her K-9 partner Robo are on a final duty call in the Colorado high country before she leaves on vacation to meet her long-lost sister and grandmother when a body discovered in a lake throws a monkey wrench in her plans.

Mattie is emotionally torn and anxious to meet the family members who may be able to explain why she, a brother and their mother were kidnapped and separated from other members of the family when she was just a child. Yet, duty inclines her to postpone her vacation to help with the investigation. Informed of her decision, Mattie's sister and grandmother insist they will come and visit her.

With the help of veterinarian Cole Walker, the victim is identified and this leads investigators to the fundamentalist religious cult of which he was a member. As clues mount, the murder of a mysterious stranger found at the site of the original crime introduces another aspect to the case. Early on, this victim had been close-mouthed, which led officers to suspect him. With his murder, Mattie and her fellow officers suffer guilt for not having pressed him to disclose what he knew.

Tensions mount with both the difficulties of the case and family dynamics. The situation comes to a head when Hannah, a young female member of the cult who has been befriended by Cole's daughter Angie, disappears. The lives of Mattie and Robo are placed in jeopardy in a thrilling conclusion to the case.

It's difficult to sustain interest in an ongoing theme in a mystery series, and this is the sixth episode in this series. But Mizushima does an excellent job in maintaining reader interest in Mattie's quest to understand how her birth family became separated as well as her developing relationship with Cole.

She achieves this by appealing to our emotions and making us care for characters who are realistically depicted and fully developed. We're as anxious to solve the mystery of Mattie's checkered past as she is and our empathy makes us want her relationship with Cole to succeed. And, of course, readers are also hooked by the love between Mattie and her K-9 partner Robo.

It doesn't hurt that puzzling crimes and solid detective work to solve them and information on the training and handling of police dogs are a bonus and, to a degree, the glue binding the whole together.

[ visit Margaret Mizushima's website ]