After five people are poisoned at a company's pre-Christmas party, the police have local coffee shop proprietor, Cara Ballard, in their sights as the prime suspect. Their investigation focuses on proving her guilty rather than investigating other avenues. They show no interest in investigating two earlier attacks on Cara's coffee shop, one of which left a staff member seriously injured, and refuse to accept all the incidents might be linked.
In a bid to ensure a thorough investigation and to prove her innocence, she engages private investigator, Sonoma (Sonny) Whittington, to undertake an independent investigation into all three incidents. Finding a motive or any other connection linking all three incidents proves difficult. In searching for potential motives that connect to the coffee shop as well as the Christmas party, Sonny must dig into the backgrounds of a number of people. As a result, Sonny twice finds her life on the line.