The Sun King Aquilan Fairlynn's nephew Darcassan has disappeared into the ruins of Chicago in search of a rift to purple-towered Illithor. Darcassan seeks the great weapons and magics that the dread Night King Xelroth Vex left behind in that sleeping, dreaming, dangerous city in the Under Dark.

Declan, Finley, Aquilan, Rhalyf, Elasha, Helgrom, Snaglak, and Glom all agree to track Darcassan and stop him from intruding on the Night King's beloved city. For if an Aravae lord steals even a grain of sand from Xelroth Vex it could spell war between the Night and Sun Elves after millennia apart.

But this quest to save Darcassan starts in motion the fates of many of its adventurers...

Declan Wilde suspects that there was something wrong with him. In the Under Dark, he will find out exactly what that is.

Finley seeks magic that humans can wield. Will he find it?

Aquilan is haunted by his parents' deaths and his own spotty memory. Are the two connected?

Rhalyf has been desperate to hide the fact that he is a Kindreth–and not just any Kindreth–but the nephew of the Night King himself. Will he keep his identity in the shadows or must he finally step into the light?

Helgrom is returning to the Under Dark after many centuries or is it far longer than that?

Elasha must stand up to her twin. Can she do it? Or will she back down as always?

Even Snaglak and Glom seem to be hiding secrets that the Under Dark's velvety blackness hints at.

One thing is for certain, nothing for the best friends–or anyone who accompanies them into the wondrous and terrifying Under Dark–will ever be the same.