"But he did say that the character would be on the sidelines in movies One and Two, and move into the middle with number Three, but I didn't realize he would move in with quite such a bang"

This quote by Ian McDiarmid is describing his character, Emperor Palpatine, in the Star Wars franchise. McDiarmid is revealing his surprise at the effect Palpatine had in the third film, Return of the Jedi. He indicates that Palpatine was just meant to be a minor character in the first two motion pictures, however his function was greatly broadened in the 3rd film. McDiarmid is revealing his surprise at the sudden and remarkable entryway Palpatine made in the 3rd film. He was not expecting Palpatine to have such a large function in the movie, and he was surprised by the impact Palpatine had. McDiarmid's quote is a testimony to the power of Palpatine's character and the impact he had on the Star Wars franchise.