A few days before shooting [Rebel Without a Cause] began, Jimmy disappeared. No one knew where he was and Warners was frantic, threatening to suspend him. Then about one morning at about four o’clock my phone rings and I hear this, “Mmmmooooo.” I knew it was Jimmy and I mooed back. He asked me if I thought he should do the movie, and I told him, “If you did it and were miserable in it or if the picture turned out badly, then it would be on my head, and I couldn’t take that responsibility.” I told him they were thinking of suspending him. Jimmy just said, “Well, I’m not coming back. Talk to ya.”
He was gone about ten days, and then one day he just showed up at my office and looked at this perfectly blank wall, stood back pretending to admire an imaginary painting. I think he was looking at Picasso’s Guernica. He asked me if it was real or a reproduction, and I said, “Oh God, its real of course!” And he said, “Well, you writers… and just because you’re a nephew of Arthur Lowe…” But he never talked about where he’d been or why he’d come back.
I don’t know what scared him, but I know he was scared. - Stewart Stern, screenwriter