Books six through nine, including Unlocked Book 8.5, of the New York Times and USA TODAY bestselling Keeper of the Lost Cities series are now available together in a collectible paperback boxed set!

Sophie Foster is struggling. Grieving. Scrambling. But she knows one thing: she will not be defeated.

The Neverseen have had their victories--but the battle is far from over. It's time to change tactics. Make sacrifices. Reexamine everything. Maybe even time for Sophie to trust her enemies.

All paths lead to Nightfall--an ominous door to an even more ominous place--and Sophie and her friends strike a dangerous bargain to get there. But nothing can prepare them for what they discover.

Sophie must face down ruthless enemies, uncover secrets of her past, and discover the true meaning of power...and evil.

Unlocked Book 8.5 offers alternating perspectives from Sophie and Keefe following the events of Legacy and includes a comprehensive guide to the world of the Lost Cities--plus fun bonuses like recipes, a map, illustrations, and more!

This astonishing paperback boxed set includes:
Nightfall
Flashback
Legacy
Unlocked Book 8.5
Stellarlune