Seasons in the Mist — Deborah Kinnard

Bethany Lindstrom is well on the way to achieving her goals as a graduate student in medieval history when her trip to Oxford goes awry. On an unplanned visit to Cornwall, while wandering around her hostess's ancient home she stumbles through an unseen portal into the fourteenth century. Stranded in 1353, Beth knows she must find a way back to her own time or face a life of falsehoods and peril. But with the stern overlord Baron Michael Veryan, she is swept into the intrigues of King Edward's court, which will test their mettle and their faith in God to the limits -- and forever bind their lives together.