From his death bed, the old owl Ezylryb warns Soren and the great tree's new king, Coryn, of a coming danger, and instructs them to read the Legends of Ga'Hoole so they will know the identity of this mysterious rising threat.
The first of these three ancient volumes is entitled "The First Collier." In it, Soren and Coryn find a world of chaos, warring kingdoms, and nachtmagen, the dark magic of the evil half-crow, half-owl creatures known as hagsfiends.
When good King H'rath is murdered by the foul hagsfiends, his mate Queen Siv knows she must give up her egg if it is to survive. The hagsfiend Ygryk knows that within the egg is a very special owl, and she wants nothing more than to steal it and turn the chick within to evil. To rescue her chick, Siv gives the egg to noble Grank, the first collier, so he can raise it far from the hagsfiends' harm.
Lasky was very elaborate with the characters names like: H'rath, N'yrtghar. Doing this was part of her creation of a new Scottish/ German owl language called "Krakish." This shows the creativity of the author when they are able to "make up" a whole language (in fact she made two).
By the tale’s end, Soren and Coryn discover what Ezylryb intended them to learn: that the evil is not confined to the time of legends. An ancient malevolence has been loosed from the past that will threaten the very existence of the great tree.