The Enduring Flame Trilogy is a three-novel fantasy

Fantasy

Fantasy is a genre of fiction that commonly uses magic and other supernatural phenomena as a primary element of plot, theme, or setting. Many works within the genre take place in imaginary worlds where magic is common...

 series, that continues the story covered by The Obsidian Trilogy

The Obsidian Trilogy

The Obsidian Trilogy is a three-novel fantasy series, chronicling the journey of Kellen Tavadon in relation to the third war between the Light and the Endarkened, co-written by Mercedes Lackey and James Mallory...

. This tale takes place over a thousand years after the conclusion of The Obsidian Trilogy and chronicles the journey of Tiercel Rolfort and Harrier Gillain as they discover that Tiercel has become a Mage of the High Magick.He and Harrier must journey to the Isvanei Desert, to stop an unknown enemy from resurrecting an ancient evil. The novels are co-written by Mercedes Lackey

Mercedes Lackey

Mercedes "Misty" Lackey is a best-selling American author of fantasy novels. Many of her novels and trilogies are interlinked and set in the world of Velgarth, mostly in and around the country of Valdemar...

 and James Mallory. The series began with The Phoenix Unchained

The Phoenix Unchained

The Phoenix Unchained is the first book of Mercedes Lackey and James Mallory's The Enduring Flame Trilogy. Its sequel is The Phoenix Endangered.-Plot summary:...

, released in 2007, continued in 2008 with The Phoenix Endangered and ended with the final book, The Phoenix Transformed, which was released in 2009.