Duquette is a supporting character in Tiberian Twilight.
He is a mysterious agent, working for an undisclosed employer. He has a very calm and serious demeanor, with a menacing voice. He also has great authority, as he dismisses GDI military police.
After Cmdr. Parker is incarcerated for his participation in Louise James' coup and placed in a GDI Supermax Facility somewhere in the Arctic Circle, Duquette arrives, waking him from his slumber and springing him from the prison. He gives him a case with a spare GDI uniform, a pistol and a GDI pass card, mentioning that he has 10 minutes to get out of the facility uninterrupted. During the mission itself, he offers aid by designating objectives. 
- Duquette has the appearance of a classic G-man.
- It is possible that Duquette's employer is in fact Kane, who needs Parker's optical implant in order to activate Threshold 19. This is supported by the fact that Johann Pascal was killed shortly before Duquette's appearance, leaving Parker the last living person with the implant.
Duquette appears in Tiberian Twilight