Woman reports a pickup truck bumped her car. When she stopped, they stole her purse. On patrol they spot a stopped car with the hood up. Driver says his engine over heated but a stakeout shows him meeting with a counterfeiter. A call about loud noise results in a citizen chewing out the officers. A scuffle at a food drive-in results in the arrest of a man for outstanding warrants. A cruise by the house with noise turns up the pickup and two men who robbed the woman.

They are on a stake out for an armored truck robbery but the thieves make a clean escape. A call to the bus station about a potential rattlesnake in a suitcase turns out to be an electric toothbrush. They make contact with their source T.J. about the robberies and he a provides a few extra details as to where he overheard the threat. A call to the same bar puts them onto a man they suspect might be involved but with no proof. Malloy develops a theory on how the robberies are committed involving the sewer system. They plan a stakeout based on Malloy's theory which they execute with success.