Don and his agents must uncover who interfered with a counter-terrorism exercise before deadly results occur.

A week-long series of counter-terrorism exercises are put to the test by Homeland Security in Los Angeles, but when the first one is violated by someone who releases a potentially lethal gas in the subway system, Don and his team are called in to find the culprit. Further investigation leads them to an unlikely suspect trying to prove a point about the city's lack of preparedness.