The Ashtown Burials Series (Random House), written by N.D. Wilson, focuses on the two siblings Cyrus Smith and Antigone Smith who get involved with a secret society called The Order of Brenden, while fighting the villains Dr. Phoenix and Radu Bey. It is named after the prisons or burials of the transmortals located in Ashtown.
In the first book of the series (The Dragons Tooth), published in 2011, the two swear an oath to an order of explorers who have long served as caretakers of the world's secrets, keepers of powerful relics from lost civilizations, and jailers to unkillable criminals who have terrorized the world for millennia. They search for their missing brother Daniel Smith while trying to earn their places as Journeymen of Ashtown.
In the second book of the series (The Drowned Vault), published in 2012, Cyrus and Antigone have lost the tooth to Dr. Phoenix. The Tooth is the only object in the world capable of killing the long-lived transmortals, and Phoenix has been tracking them down one-by-one, and murdering them. When the surviving transmortals, led by legendary warrior Gilgamesh of Uruk, descend on Ashtown demanding justice, Cyrus and Antigone find themselves on the run in a desperate search to locate Phoenix and regain the Tooth. In the process, they uncover an evil even more dangerous than Phoenix, one that has been waiting for centuries to emerge.
The Empire of Bones, released in 2013, is the third book in the Ashtown Burials series. In this book, and Cy his sister Antigone are trying to discover what they have inherited from their godfather, William Skelton, as they remain on the run from the corrupt Order of Brenden. They and their friends are all that stand between Radu Bey opening the Burials and Phoenix taking over the world. At last, they stop running and take a stand in Ashtown itself.
The fourth book in the series, The Silent Bells, is still not published, even though it is believed to be finished. This is because N. D. Wilson's publishers retired mid-series and the new publishers do not like the book in its current format. However, N. D. Wilson is determined to publish the book, saying that he would do it, "even if I have to publish it line by line on Twitter."