five opens, Don asks Amita and Larry to help with the math since Charlie no longer had his clearance, which neither brother wants to fight for. After Charlie helps the team find Don during a shootout on a mountainside and find a victim, Don decides to tell Charlie to ask for his clearance back. When they do begin the process of getting Charlie's clearance back, Don learns that FBI Security Officer Carl McGowan (Keith Carradine) wants to open an investigation into Don instead of opening an investigation about Charlie's e-mail to Pakistan. In the formal interview, Don tells McGowan to reinstate Charlie's clearance, or Don quits the FBI. McGowan recommends disciplinary action against Don for his actions during the Crystal Hoyle and Clay Porter incidents, which Don expects. When the ADIC overturns McGowan's recommendations about Charlie and Don, Don is glad that Charlie is working with him again but feels lost in regards to the recommendation concerning him. The fight with McGowan, coupled with seeing a fellow agent reach out for a picture of his family before dying in a shootout, causes Don to explore Judaism. His decision surprises his family and Robin. Buck Winters breaks out of prison to go after Don, causing Don to fear that he may have to shoot Buck. After Charlie tells him that he cannot go back in time and reverse his actions, Don then makes a plan to capture Buck alive. Don, the team, and Buck go into the temple where Buck reveals that he wanted a death-by-cop. The team arrest Buck. When Charlie gets an offer from DARPA, he confides to Alan that he does not know whether he wants Charlie to take it. Don later tells Charlie that there was a better offer with the FBI. Don also teams up with Larry to tell Jane Karellen that Charlie was not taking DARPA up on their offer. Toward the end of season five, David applies to be Don's primary relief supervisor. Don first leaves the letter of recommendation on his desk for David to read. After the request is granted and some on-the-job training in being Liz's handler, Don breaks the news about the request to David. Don asks Charlie to help him during a home invasion case. Charlie's results confirm the area that the suspects would hit next. While checking out the property after a gun battle with the four suspects,