He wrote a novel, and no sooner did he have the synopsis of a story ,but he would invite a crowd of his
friends outdoors and read it aloud to them.
译文：他写小说时刚刚构思出剧情轮廓就赶紧邀请一群朋友到野外，然后把剧情梗概大声地念给他们听。
这句话and 和 but 是怎么个用法？不是no sooner...than...吗？怎么冒出来个but？还有前边的and是怎么回事？