Told in multiple voices, fifteen-year-old Jamaican Louisa Adair uncovers an Enigma machine in the small Scottish village where she cares for an elderly German woman, and helps solve a puzzle that could turn the tide of World War II.

Thanks to a DNA test, Avery Grambs knows that she is not a Hawthorne by blood, but clues pile up hinting at a deeper connection to the family than she had ever imagined. Grayson and Jameson, the enigmatic and magnetic Hawthorne grandsons, continue to pull Avery in different directions. Tobias Hawthorne left his entire fortune to Avery, a virtual stranger, rather than to his own daughters or grandsons ... and there are those who will stop at nothing...