The Tinker Tailor Solider Spy star told Digital Spy that the thing he will miss most about playing Jim Gordon is working with the same cast and crew.
"It's been seven years, maybe more since we did the first one. You miss the people, there's a loyalty to Chris and there's a lot of people that work with him all the time," he said. "Actors do come and go, but apart from the mainstays of Michael [Caine], Morgan [Freeman] and Christian [Bale] the crew is the same, from the caterers to the camera operator.
"It's like reuniting with a family, that was sad, I miss that. We will go out with a bang, I'm sworn to secrecy but it's a great story. An epic conclusion."
Tom Hardy, Anne Hathaway, Joseph Gordon-Levitt and Marion Cotillard will star in The Dark Knight Rises, opening in cinemas on July 20, 2012.
Oldman's Tinker Tailor Soldier Spy is released on DVD and Blu-ray on January 30, 2012.
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Watch the Dark Knight Rises trailer below: