The Den of Shadows series includes nine contemporary young adult novels, two related series and three short stories published between 1999 and 2016. Though the series has concluded, Amelia has discussed returning to the characters and the world in the aftermath of the final contemporary novel, Promises to Keep, at some point in the future.
Though the contemporary Den of Shadows books are a series, and take place in the same world in and in approximately the order of their publication, they are mostly designed to stand alone (the exception is All Just Glass, which is a direct sequel to Shattered Mirror). They can be read out of order, but they do build on each other, and long-term readers will find cross-references and times where events from one story have triggered the events in the next.
The complete series, in order of publication, includes:
Return to Den of Shadows
"The Assassin"* (tentative)
* "Empire of Dirt" is a short story featured in the anthology 666: The Number Of The Beast. "Rebel," "Prophet" and "Assassin" are e-short companion stories to the Maeve'ra Trilogy.