The cast of Aliens works together so perfectly, it's hard to imagine that one of them was a last minute replacement. The cast rehearsed together for weeks, personalizing their guns and costumes, and trained together to feel like a real team. But James Remar, who was to play Colonel Hicks, had to leave abruptly.
For years, Remar said he left to attend to an emergency at home, but more recently he's told the full story. "I had a terrible drug problem, but I got through it. I had a great career and personal life, and messed it up with a terrible drug habit…I was fired after a couple weeks of filming because I got busted for possession of drugs," Remar told the Sidebar podcast (via Indiewire). Though many Hollywood stars have run ins with drugs it's pretty bizarre to have to leave a huge studio sequel for drug possession charges from another country. It's even more rare for the director to be able to find a worthy replacement.
Michael Biehn got a call from producer Gale Hurd on a Friday to see if it was available to do the film. By Monday, he was on set in London. Though he got almost no prep time, had to jump into a film that already starting film, and the cast had previously bonded with Remar, Biehn gave possibly the best performance of his career.