Scientist formerly stationed out of Area 51. Langham dealt directly with the mimetic devices snatched from the Mimetic aliens several years before. He was aware of the Committee, who he had worked for to provide alien enhancements to their product lines, but had no clue they were going to use the technology to conceal assassins (as had been done with the mimic device of Colonel O'Neill to move against Senator Kinsey).
Dr. Langham stole the mimic device of an S.G.C. staffer which he used to conceal himself, but was retrieved by Teal'c and Jonas Quinn and brought to the S.G.C. for questioning. He agreed to talk, but only if the Stargate provided him access to another world where he could escape from the Rogue N.I.D. and the Committee forever.
Smoke and Mirrors - Dr. Langham is captured by Jonas and Teal'c, taken back to Stargate Command for questioning.