The man tells the brothers that he has placed seven bombs under the bridge and will detonate them unless Charlie answers his questions correctly.
At the office, Don discusses the case with FBI Special Agent Megan Reeves (Diane Farr), who had just returned from her temporary assignment with the United States Department of Justice (DOJ).
Investigation into the man's background reveals that their suspect is Taylor Ashby (Martin Jarvis), a former triple agent who preferred old-school cryptography to more modern mathematical methods.
They then go to visit Dwayne Carter (Shawn Hatosy), an army friend of Colby's who had previously been arrested by the team for murdering a woman working for the Chinese consulate and for treason,[1] in prison.
They also learn that Ashby had contacted reporter Naomi Vaughn (Catherine Dent) at a Los Angeles newspaper about the Janus list.
Using G major and the Bacon ciphers, Charlie and Amita uncover the hidden voice-mail account that Ashby used to pass the Janus list to Vaughn.
While Megan and Colby fight the assassins who attempt to kill Vaughn, Don, David, back at the office, Charlie finally cracks the code which is a voice message of Ashby revealing which agents are betraying their respective countries.
As they listen, Charlie and Amita are stunned to discover that Colby's name is included on the list and that he is a spy working for the Chinese government.
At the office and with Don interrogating as Megan and David look on, Colby acknowledges that he has been spying for the Chinese for the two years that he has been on the FBI team.
[9] Unknown to fans, the producers told Bruno what would happen to Colby and the storyline's resolution several episodes in advance and asked him not to tell anyone else.
[14] In 2009, David Hofstede featured Colby's arrest as question 637 in his book Obsessed with TV: test your knowledge of every channel.