Burn Rate (S03E20)

While on the hunt for a serial letter-bomber, Don and Charlie disagree over whether a suspect, who had eluded conviction years earlier, is the person responsible for the latest murder. After analyzing the suspected serial bomber’s background, Charlie realizes he has a lot in common with the man intellectually. He questions whether they've got the wrong guy but Don thinks Charlie's emotions are clouding his judgment. Whoever the culprit is, it's only a matter of time before he strikes again. (iTunes)