When a number of people with no criminal history have bizarre violent episodes, Hood and Rachel travel to White Tail Hills, Texas to investigate. They pursue a number of leads, but when Hood has his break with reality, he realizes the source is the city water. However, since not everyone is affected, they must determine what causes the water to be contaminated. Their investigation leads them to a drug smuggling group who laced plumbing pipes with PCP, but a shipping discrepancy sent the pipes to someone who installed them in people's homes.