Almost two years after the world doesn't end, Castiel falls from grace-and loses his voice in the process. A time for confession and change awakens; before long, Castiel is settling into a loving relationship with Dean.
Castiel and Dean are tired, and hunting for a place to stay permanently together, and fall in love with the strange little house on the end of Swallowtail Drive. For a little while life is as it should be-sweet, affectionate, and beginning afresh.
But more and more Castiel sees and hears things in the house that beg the question of whether or not a place itself can be alive. The walls and rooms seem to shift and grow and breathe, and one night, Dean comes home from a hunt changed in a way that Castiel cannot explain. In the months that follow, their domestic bliss takes turns for the dark and sour, and the confusion of their circumstances will ultimately test everything Castiel knows about the man he loves, and everything he believes to be true.