From back cover:
The good dragons of Krynn need help. Recruited by the silver dragon Saramber, the player characters have joined ranks with the dragons and sought to solve the mystery behind the deaths of many silver and bronze dragons and passed the tests set out for them, earning the trust of these ancient creatures.
But now, Saramber fears evil dragons have discovered the portal that could lead them to the dragons' homeland. If this is true, they must be stopped before they can launch an attack that could destroy this fabled dimension. The adventure leads player characters from the plains of Lunitari to the depths of the ocean and the abode of monstrous Artha, banished daughter of Takhisis.
This third module brings to a climax the epic tale begun with In Search of Dragons, and continued in Dragon Magic. On success or failure hangs the fate of tone of the noblest races of Krynn.