From the Back Cover
Worlds kept them apart.
Destiny brought them together.
Outside the dome of Reverie, Aria and Perry are struggling to keep their people from tearing each other apart. Their situation is desperate, and with the Aether storms worsening time is running out for them to rescue Cinder from Hess and Sable.
Cinder is both the key to unlock the Still Blue and their only hope for survival, so Aria and Perry assemble an unlikely team to attempt a daring rescue mission. They know that in a dying world, the bond of friendship is what matters most.
In this final book in the Under the Never Sky trilogy, the stakes are raised to the absolute limit and Aria's love story is brought to an unforgettable close.