S2, E7: When the number of violent home invasions in an upscale neighborhood begins to escalate, Don and his agents are called in after it is discovered that the victims are being tracked through the GPS in their cell phones. To help solve the case, Charlie applies a data-mining procedure to find a link between the robberies and uncovers a connection between the victim's insurance and wireless companies, exposing a much larger operation. Meanwhile rival mathematician Marshall Penfield challenges one of Charlie's mathematical findings, which makes Charlie question whether he is spending too much time working with the FBI and not enough time making strides in his own field. Colin Hanks guest stars.