After a murder is committed in a San Francisco park, the Chief takes part in a live TV broadcast in the hope of provoking such a panic in his prime suspect that the man will make a mistake, or lead Ed to some hard evidence.

The promotion of a new Chief of Police leaves an opening for a new Chief of Detectives, and the front runner for the job is Lieutenant Amy Prentiss. Much of the force is opposed to her appointment, but she is determined to prove them wrong. With Ironside and his team alone in supporting her, she has to make her mark in a difficult case beset with problems, whilst at the same time convincing her male dominated staff to accept her as their new leader.