Almost forty years ago, Heather Davenport unearthed two bodies in a shallow grave on her grandmother’s ranch. Now retired from the FBI and still haunted by the murders, Heather is willing to do anything—even beg the help of the mysterious Mercury Group. But a killer is watching. And in a town built on this many lies, no one will be safe when the dark truth comes to the surface.

Colorado, 1943: With a brother gone to war, Dinah must learn how to fend for herself. She spends her days working an abandoned mine and her nights longing to escape her dying town. When Dinah sees a young soldier out in the snow—a soldier who looks just like Edward Gainsbury, a man who supposedly died in 1918—she follows him into the woods. But what she discovers will force Dinah to confront the true history of her town and the dangerous darkness hiding inside those she least suspects.

Stel Alaster has never known life without the Corridor. It appeared suddenly seventeen years ago, the only portal to a parallel version of our world—Second Earth. When the Corridor starts to fail, emitting erratic bursts of energy that could destroy First Earth, Stel must risk everything to save the people and world she loves. The fate of every world lies in the balance. . . .