Detective Wade Jackson is in for a shock when he's summoned to the police chief's office--his sergeant has been poisoned, and Jackson's been tapped to lead the investigation.

But before the Eugene Violent Crimes unit has a chance to respond, two people are gunned down at a licensed marijuana nursery. Jackson and his colleague Detective Lara Evans are on the case--but there are more suspects than evidence, and the crime is baffling.

Soon, more people are hospitalized, and when Evans discovers a link between the poisonings and edible pot, she and Jackson suspect that the product...