Called to the scene of a grisly double murder in a Northern English village, Detective Inspector Dave Barnes thinks he's seen everything—until the threads of his investigation unwind an otherworldly secret.

As the Inspector and his team delve deeper into the case, a former history professor, with a personal interest in the crime, steps forward to provide bizarre clues that seem too impossible to be true. And, as Professor Claire Tulley shares her discoveries dating back to a failed military experiment 90 years earlier, DI Barnes realizes that he's embroiled in a cover-up that reaches the highest levels of the government and beyond.

On a parallel Earth, Colonel David Barnes observes his doppelgänger with contempt as the detective edges closer to learning the truth about alternate worlds and the multidimensional portals that link them. But, as the colonel seeks to assume control, he will do whatever it takes to overcome those in his way, even if that means assassinating the man reflected in the mirror.

With the fate of his Earth at stake, and realizing that not everyone around him is who they appear to be, Detective Inspector Barnes and his team must battle for their survival. But how can he win the fight when his own reflection is plotting against him?