From 14 to 25-years-old, Sam Martin's an afterthought in Nimbus. All this world wants is for him to leave, for him to go outside the steel doors and survive in the vicious, untamed wilderness for 11 years. After all, every person who has ever called Nimbus home has done it. Every. Last. One. Or so he was told. Outside the walls of Nimbus, Sam's faced with horrors unimaginable to someone who's spent his whole life stuck behind the steel. Now, he must fend off evils he's never seen, horrors he never could have expected—all while fighting himself. After all, he's just a kid. A kid who never knew how heavy fate could truly be.

It’s been three months since the events that transpired in Nimbus. Three months in which Sam, Sean, and Elise have tried to get over the nightmare that wanted to kill them; the same nightmare that ended the lives of those they loved. Now, time is up—somewhere else is calling them; somewhere else desires to test their strength. A new place beckons for Elise to learn its ways. It pleads for Sam not to shy away from the horrors he may experience. It begs Sean to show his strength when he least believes he can. And the longer they wait, the stronger the call becomes; the more it dares to make them suffer until they find and answer it. In Halcyon, Sam, Elise, and Sean search for a new world, a new home by leaving everything they’ve ever known behind. With no clue what lies ahead, will they discover a new society and a new way of living, or will their haunted pasts catch up with them?

With only one known region left to experience, will Umbra prove it's found perfection, or will it be just another nightmare for Sam, Sean, and Elise to overcome?