Until the Celebration Author:Zilpha Keatley Snyder The third book in the Green-sky trilogy by three-time Newbery Honor Award-winner Zilpha Keatley Snyder. The banished Erdlings are reunited with the Kindar of Green-sky. But trouble ensues when the two peoples resist the inevitable changes in their lives and attitudes that the union demands, and the Holy Children Pomma and Teera disappear.