Mapping the Interior by Stephen Graham Jones (w/ signed bookplate)

Walking through his own house at night, a young boy thinks he sees another person stepping through a doorway. The figure reminds him of his long-dead father, who drowned mysteriously before his family left the reservation. When he follows, it he discovers his house is bigger and deeper than he ever knew.

The house is the kind of wrong place where you can lose yourself and find things you'd rather not have. Over the course of a few nights, the boy tries to map out his house in an effort that puts his younger brother in the worst danger, and puts him in the position to save them . . . at a terrible cost.