Star Trek: Insurrection/WMG

Michael Dorn just walked on set.

This film offers no explanation for why Worf is in it. He literally just shows up and they go with it. My guess: Michael Dorn initially refused to do the film, but got lost on his way to the set of DS 9 and happened to walk into Patrick Stewart while filming that corridor scene in the opening. Why waste such a good take when you can just throw him in.