Old Soldiers is the tenth episode of the sixth season. It was released on 4 December 2009.
When the team foils a robbery of an armored car full of Federal Reserve money and recover bills that trace back to the infamous D.B. Cooper heist, they call on Agent Roger Bloom, who worked on the Cooper case, for help with the investigation.
This is one of the few episodes that tackles head-on the difference in mentality between Don and the other two Eppes men, although all three seem to end with an acceptance by each of the right of the others to hold the views they have. Alan and Roger Bloom, having lived through the sixties, are in many ways representative of the differing perspectives, and they also arrive at a détente.
When Nikki brings her gun to bear on Till, the sound of a hammer being cocked is heard. The Glock is striker-fired and does not have a hammer.
When Amita holds up a bill of the D.B. Cooper currency to the others and flips it to show both faces, it's clear that it is fake in that it is printed like a coin where the top edge of the reverse is the bottom edge of the obverse.
[This appears on the beginning of the episode] 9800 feet in the air 28 square miles 50000 bills 38 years