The Immortals was the tenth Edge Chronicles book. It was not part of the Rook, Twig or Quint trilogies, but rather tied together all of the loose plot points from the three and was meant to be the final book. It took place 300 years after the start of the Third Age of Flight, and 500 years after the time of Quint.
The story followed a young lamplighter from the phraxmines of the eastern Deepwoods named Nate Quarter. His job was difficult, but he was well paid for it. One day, the Mine Sergeant, Grint Grayle, had enough of him and decided to have him killed, but he managed to run for it and set off for Great Glade with a young scuttler named Slip.
Nate and Slip found work in the district of Copperwood, and became well-settled, but Felftis Brack and Branxford Drew framed him for the murder of Friston Drew, and they fled for the Midwood Decks, accompanied by a banderbear named Weelum and the phraxmine owner's daughter, Eudoxia Prade. At the Midwood Decks, Nate and his friends caught a phraxbarge to Hive called Old Glory to help find Eudoxia's father. During a rescue attempt for him, Eudoxia and Nate got mixed up in the rising tension between the cities of Great Glade and Hive, and he and Eudoxia were forced to join the Hive Militia. Eudoxia was badly injured in a great battle and had a bullet lodged behind her right ear, so Nate set off for the city of Riverrise aboard the skycraft of Zelphyius Dax.
Upon arriving at the city, Nate soon realized that healing Eudoxia would be very difficult. The Riverrise Custodians restricted the flow of the potent Riverrise water, and the Custodian General, Golderayce One-Eye, was hoarding most of the water for himself. Nate, accompanied by Golderayce's gabtroll assistants, Gilmora and Gomber, sneaked into the Garden of Life, but were caught by Golderayce. Golderayce fired a poison dart at Nate, but the Caterbird suddenly swooped from out of nowhere, creating a whirlwind that blew the dart back at Golderayce. Nate proceeded to the Garden of Life, and discovered that two of the "Immortals", Rook and Twig, were being held prisoner there. After explaining their stories, Rook and Twig were swept up into a Great Storm, were transformed into echoes of their youth, and reunited with Quint.
Not long after, Nate, accompanied by his friends and Ambris Hentadile (also known as "The Professor"), traveled to the Edge in search of Ifflix Hentadile, and discovered the fabled "city of shining spires"--Sanctaphrax, blown back to the Edge after centuries of wandering in Open Sky. They discovered that old Sanctaphrax academics were greeting Deepwooders who were lured into the city. However, it soon became apparent that the academics were actually an army of Gloamglozers, created in the Ancient Laboratory by the original Gloamglozer himself. The Gloamglozers attacked, but the Great Storm swept over the ruined city, and Quint, Twig, and Rook arrived, destroying the Gloamglozers once and for all and curing stone-sickness.
After the battle, the three Immortals turned into glisters to begin their lives anew.
The Caterbird then arrived, and explained to Nate about the three most ancient entities in all of the Edge: the Sanctaphrax Rock of the earth, the Great Blueshell Clam of the water, and the Caterbird of the sky. These ancient, omniscient beings, the Caterbird said, were the first of the glisters to arrive at the Edge. The Caterbird explained that all life on the Edge begins this way, except for the Gloamglozer, whose creation spawned stone-sickness. Then, the Caterbird, now freed from its debt to Twig, left Nate to begin its rebirth cycle. Nate then decided to join the Professor and descend below the Edge to discover awaiting mysteries and wonders, much to Eudoxia's dismay. She told Nate to return to her and he promised to do so. The novel ended with Nate and Ambris descending into the black abyss and disappearing into the darkness below.
Fans of The Edge Chronicles eagerly awaited this then considered final installment. The Immortals was originally scheduled for release in September 2008, but was delayed until February 2009. The Immortals added an entirely new dimension to The Edge Chronicles. Whereas the previous books were based loosely on society in the 18th century, combined with naval warfare tactics from far earlier periods, The Immortals more closely resembled a 19th-century society and parodied the Industrial Revolution. The book's physical setup was also quite different. The Immortals was far longer than any of the other books in the series. Its chapters were also shorter and did not have unique names.
These differences, however, did not create any sort of negative reaction. The general reception to The Immortals was quite positive, and fans of the series were not disappointed.Even though the Immortals could have provided a fine ending, the authors continued with the blog Weird New Worlds. When this blog received widespread attention by fans of the Edge Chronicles it was turned into another trilogy, the Cade Saga, the first book The Nameless One being released in 2014.