The Condemned by Irina Shapiro

2015. Dr. Quinn Allenby thinks she’s seen it all, but when the remains of a young woman and her newborn are discovered in a cave in Cornwall, the only clue to her death is a smooth-edged hole in the top of the skull and the indisputable evidence that the victim was still alive, and possibly in labor, when the coffin was sealed. Torn between her professional commitments and her desperate need to find her missing twin, Quinn agrees to a daring plan, one that will lead to the Taliban-occupied mountains of Afghanistan and the snow-covered alps of Germany.

1620. After suffering years of abuse at the hands of her uncle, Mary takes the ultimate risk and sails for the New World, where the promise of a new life and an arranged marriage to a colonist await. Mary is determined to make her marriage a success, but her husband’s indifference drives her straight into the arms of the one man she thought she could never love.