Dr. Erica Merrill, a young vet trying to establish her veterinary practice in her hometown, a small Northern Idaho county seat, gets involved in a murder investigation when a drug she has dispensed for a family dog is used to poison a wealthy widow. A battle over inheritance means that everyone involved with the household has a motive. But only the nine-year-old granddaughter has both means and opportunity. Neither Erica nor her deputy sheriff boyfriend, Clay Caldwell, want to believe that a child would murder her grandmother, but they wonder if her father could have persuaded her to do it. Erica must also contend with her father, who wants to run her life, a disgruntled colleague who reports her to the licensing authority, and a new physician in town with amorous intentions. It is Erica's knowledge not of the affect of the drug on the victim, but on the dog, that allows her to solve the mystery
There is one set of tracks leading to and from the snowbound cabin of Eugene Pettijohn, dead of a gunshot wound.These tracks were made by Herb Shultz, the unpopular deadbeat neighbour who discovered the body. Shultz is arrested but Dr. Erica Merrill, a young veterinarian trying to establish a practice in her hometown, doesn't think Shultz committed the murder. Her boyfriend, deputy sheriff Clay Caldwell, is skeptical; her powerful father interfering; and citizens of the small Northern Idaho county seat, antagonistic. Her fledgling veterinary practice threatened, Dr. Merrill decides that she must solve the mystery herself and win acceptance as a person in her own right.