[1] Leaving the show after the first two series, Duncan then appeared in the 1988 television adaptation of The Hound of the Baskervilles, starring Jeremy Brett as Sherlock Holmes.
[citation needed] Duncan's next key role was in the 1992 science fiction film Split Second.
[2] Since the early 2000s, he has been doing voiceover work, including films like Batman Unlimited: Animal Instincts and video games like Warlords Battlecry, Legacy of Kain: Defiance, X-Men Legends II: Rise of Apocalypse, Tomb Raider: Legend, Tomb Raider: Anniversary, Final Fantasy XIV, Mass Effect, Infinity Blade II, Infinity Blade III, Metal Gear Rising: Revengeance and Middle-earth: Shadow of Mordor, as well as animated television series: Alfred Pennyworth in The Batman and Adrian Toomes in Marvel's Spider-Man.
[citation needed] His most notable television guest appearances include episodes of Tracey Takes On..., Buffy the Vampire Slayer, Charmed, Angel and Leverage.
[3][4] In 1994, after beginning to find regular work as an actor, Duncan relocated from the United Kingdom to Los Angeles, California.