The Keys to the Kingdom was a cancelled sourcebook for Changeling: The Dreaming.
Summary[]
From the White Wolf Game Studio 2002 Catalog, Jan-Jun:
Casque of Triumph, Casque of Sorrows
So deadly, its opening decimated the Tuatha de Danaan, yet long ago the key to the Triumh Casque of Sorrows was shattered, its pieces scattered to sew dissention among the Fomorians' enemies. Who holds the key has the power. The Casque awaits. From mysterious Egypt comes word of a potent item - part of the key? Could the casque restore Concordia, assure a commoner victory or destroy all? And if you don't seek its power, who will?.
The Allure of the Unknown
Keys to the Kingdom gives players and Storytellers alike the chance to delve into mysterious and fabled fae lands little known to the changelings of embattled Concordia. The story moves from timeless, sun-baked Egypt to the emerald jungles of the rainforest, featuring people and places never before detailed in Changeling: The Dreaming. - pg. 8