"Alan Rickman was such a terrific actor, and that was such a terrific character that he played. And it was a joy to be with him. We used to laugh together because we ran out of reaction shots. They were always - when everything had been done and the children were finished, they would turn the camera around and we'd have to do various reaction shots of amazement or sadness and things. We used to say we'd got to about number 200-and-something and we'd run out of knowing what to do when the camera came around on us. But he was a joy."