[ZodWallop]

Here After by Sean Costello is $0.99 at Amazon.

Following the death of his ten-year-old son, physician Peter Croft embarks on a desperate, seemingly random search for a missing child, risking his sanity, even his life in a grief-induced quest. His journey propels him into the darkest reaches of human suffering, and pits him squarely against an adversary whose own obsession defies all reason.