Going to the Bureau

Leaving your office early, under the pretense that you're traveling to another facility ("the bureau") to continue working.....when in reality, you're leaving to go home; presumably to eat cake and admire your front butt.

Ed: Are you going with us to Starbucks today at 2:30?

Mark: No, I'm going to the bureau here in a little bit. I've got a lot of work to catch up on.

Ed: Right. (Makes Air Jerk motion)