The Last Haven - The Lost Land Series, #3

Genevieve MacGregor has tried to move on from the untimely loss of her beloved husband Nate, two years past. Still, her family worry as they see the vibrant woman they knew, slip deeper into a melancholy shell. Neil, scientist and family friend, is burdened with guilt and can't bear to see the haunted look in Gen's eyes. When he hears an explosion on the northern border of the valley, Neil is first on the spot to investigate.
An old woman's dying words dare to give him the hope he has been praying for. The only problem being that this Holy Grail of Redemption with Gen appeared to be residing in the Hell on Earth he had escaped from, seven years ago.