Urban Exploration. The practice of investigating areas not designed for public use. With 850 years of history lurking beneath its streets, including Ivan the Terrible's torture chambers, Soviet bomb shelters, and Stalin's fabled Metro-2 subway system, Moscow is the ultimate off-limits adventure zone. The perfect place for a man to put his past behind him.

And that is exactly what Nate, grief-stricken over the death of his young daughter, sets off with his wife Adrian, and her brother Jay to do.

But strange things can happen in the dark, closed-off areas of history, and what started as a way to escape his grief quickly turns into a journey that forces Nate to confront it head-on, with nothing less than his eternal destiny hanging in the balance.