His relationship with Charlie was apparently somewhat strained even before their mother's death, as Don is stunned to learn that his little brother has enough security clearance to work with both the CDC and the NSA ("Vector"). He is even more surprised to discover that Charlie doesn't seem to know that his clearance will allow him to walk into the L.A. Office whenever he wishes, rather than obtaining a visitor's pass every time and being restricted in what he can do there. Upon resolving Charlie's status, Don now apparently calls Charlie in on most of his cases.
