When Samuels takes some time off, Chris expects to be put in charge. But a high-tech, none-""street"" officer, Lt. Thornton, gets the job. The crime case deals with construction kickbacks, so Harvey volunteers to help out by wearing a wire

Cagney and Lacey go undercover at a computer manufacturer. But the company has random drug testing and Chris flunks it. Of course, David argues that this is a violation of her civil rights.

Thornton shots a fellow officer in an operation that went bad. That's what happens when you put someone with no practical experience in charge