An arrangement was then made to bring Fox aboard even as he continued to filmFamily Ties.

It was very unusual because Christopher is a theatrically trained actor, explains Gale.

He knew every line of the script on the first day of shooting.

Back to the Future (1985)

Ralph Nelson/Universal

Foxs last-minute line-learning also worked its way into the final film.

Michael would throw Chris for a loop by saying something that wasnt originally in the script, recalls Gale.

Chris was such a good actor that he just went with it and made something out of it.

These guys became great friends.

Still are great friends.

Video courtesy of Universal Pictures Home Entertainment.