When a high school chemistry teacher and his family are kidnapped, DCO takes the case because the teacher is a former chemical weapons engineer for the Russian Army, hidden by the CIA in the Witness Protection Program. Are the kidnappers using the teacher to manufacture VX gas? Martin, Crystal and Troy Buchannan go undercover to infiltrate the Chechen mob, rescue the family and stop the production of the deadly gas.

The Colonel and Ana Paulanos are captured by DCO when they sell Martin a briefcase of VX that turns out to be bogus. In response, one of The Colonel's followers releases real VX on a crowded bus, threatening more attacks if The Colonel and Ana aren't released. As a last resort, Martin stages a pulse-pounding "false flag" prison break of The Colonel and, with Ana's help, forces The Colonel to lead him to the VX. Time will tell whether Martin can trust Ana to betray The Colonel and help him find all the gas before more civilians are killed.