At the turn of the 21st century, Dr. Sara Roberts, a newly appointed professor of a fictitious Ivy League university in Cambridge, Massachusetts, is entranced by her work colleague, the enigmatic Dr. Koleen Edwards. The two form a fast friendship until Dr. Edwards asks Sara out on proper date in the fall. Though their relationship starts out smooth, a menacing letter sent to Dr. Roberts shifts their bond in a not-so-typical way. After a fatal accident in late December, it is revealed to Sara that Dr. Edwards is a living historical figure, unaged and unmarked with time. Dr. Edwards goes on to...