The Archipelago of Dreams is no more...
But the battle to save it has just begun.
The Caretakers are at war. The Archipelago of Dreams has fallen to the Echthroi, and the link to the Summer Country has been lost. The Cabal – renegade Caretakers who have become agents of the Shadows – are amassing power to open our world to their masters. Only by rebuilding the Keep of Time can the two worlds be reconnected, but not even the vanished Dragons knew how the Keep was built, or who built it – and the Echthroi are coming. Worse, the Cabal are also training a secret weapon: the lost Prince, Coal – and they are searching for the legendary Ruby Armor of T'ai Shan, which gives its wearer the ability to control Time and Space – which could make Coal, and the Echthroi, all but invincible.
But there is still hope: the Grail child, Rose Dyson, and the new Cartographer Edmund McGee have learned how to map time, and at Edgar Allan Poe's Tamerlane House, the Caretakers Emeritus have found a trail of clues in the ancient Histories that might lead them to the Architect of the Keep. The secret lies somewhere in Deep Time at the beginnings of the World, when the Summer Country and the Archipelago were one and the same.
However, every trip into the Past must be balanced by one into the Future – and Rose promised her teacher Bert – H.G. Wells – that they would first go to the far Future, one ruled by the Morlocks, to find his lost love, the Eloi Weena. But the world of the Future is not the one Bert remembered. It has changed to a terrible place of cold order and eternal darkness. A world ruled by the Echthroi's heir: Lord Winter. But this new, terrible enemy was no stranger to them – he was once among the most trusted and beloved of their allies, and one of the great Caretakers of prophecy. The Echthroi's servant who rules the world of the Future is Jack.
In the Present, as the Caretakers and the Cabal race to find the Ruby Armor, Rose, Bert, Edmund, and the near-immortal Caretaker Charles flee the terrible Future of Lord Winter to the distant Past. There, they learn of the first great heroes' role in shaping the Archipelago: the legendary Gilgamesh; the great Jason; and Jason's wife Medea, who, with the help of the Dragon Azer, betrayed Jason and kept him from becoming the first King of the Archipelago.
The companions are nearly lost when they are aided by a strange old man who seems to exist outside of time, and who helps them make their final journey to the place where all the secrets may be found. They knew it as the Drowned Lands. History came to call it Atlantis. But at the beginning of time, it was known as the City of Jade, and it was said that the Architect of the Keep may have trained the young angel who built the city – an angel named Samaranth.