Deltora Quest 3

Deltora Quest 3, known as Dragons of Deltora or Deltora Dragons outside Australia, is the third and final series in the collective Deltora Quest series. Illustrated by Marc McBride and Kate Rowe, the series contains four books. The four books in the series were originally released over the span of 2004. In August 2007 the four books were released together in a collected volume.

Plot
"Lief, Barda and Jasmine face a terrifying race against time to find and destroy the Four Sisters, evil creations of the Shadow Lord's sorcery.

The Enemy has been exiled, but he has not yet been defeated. Thanks to an ancient plot, his shadow still stretches over Deltora.

For centuries the vile Sisters, hidden in the four corners of Deltora, have been spreading their poison and singing their songs of death and despair. Now, their work is nearly done. Deltora is free, but it is dying. Only weeds and monsters thrive. The people are starving. And the Shadow Lord gloats in his stronghold beyond the mountains, planning his triumphant return.

In secrecy and in haste, guided only by fragments of an ancient map, the companions plunge headlong into a quest that takes them to the wildest places in the kingdom, and puts them face to face with fearsome enemies. They soon learn that even the magic of the Belt of Deltora is not enough to combat the power of the Four Sisters. Their only chance is to use a dangerous secret weapon. They must wake Deltora's last seven dragons, which have been deep in enchanted sleep for centuries. Only when the mysterious power of the dragons joins with the magic of the gems of the Belt of Deltora can the Sisters be destroyed."

Trivia

 * Deltora Quest 3 takes place during late autumn or early winter. This is evidenced by Fa-Glin's coded message to King Lief in Dragon's Nest, in which he writes about the Dread Gnomes' preparations for winter: the struggles of making their crops grow, complains that hunting is poor snd says that winter on Dread Mountain will be hard. It is furthermore evidenced in Shadowgate, where, when the companions come to the village of Happy Vale, "dead leaves blew in the deserted streets", and later in the same book Lief states that he has "been eighteen for months", and his own birthday is at summer's end, as said in The Forests of Silence, the first book of the first of the Deltora Quest series.