Time-traveling PhD student Sydney Dahlquist’s first mission sounded simple enough—spend two weeks in December 1810 collecting blood samples from the sick and wounded of Wellington’s army, then go home to modern-day Seattle and Christmas with her family. But when her time machine breaks, stranding her in the past, she must decide whether to sacrifice herself to protect the timeline or to build a new life—and embrace a new love—two centuries before her time.

Rifle captain Miles Griffin has been fascinated by the tall, beautiful "Mrs. Sydney" from the day he met her caring for wounded soldiers. When he stumbles upon her time travel secret on Christmas Eve, he vows to do whatever it takes to seduce her into making her home in his present—by his side.