Kyllan willingly accepts the burden of Le'ir when his father is banished and the destruction of the City by a devastating earthquake throws everyone's life into turmoil.  The conception of his child keeps a Promise made by the gods in the Before Time and releases the Forest People from their bond to the Great Forest.  Now able to leave the Forest freely, Kyllan asks his people to help those who have lost their homes.

When an attempt on his life fails and his wife is poisoned, Kyllan takes her to One Tree in the center of the ruined City, desperately praying the magic of the legendary tree can save her life and that of their unborn child.  Failure will cost the Forest People their freedom from the Great Forest and Kyllan will pay the highest cost of all - his life.