A Druid Stone. Mórdha Stone Chronicles, #5

AJ Moore Murphy falls through the fog, landing on a familiar knoll, stranded in the middle of a war between France and England. Her worst enemy lies injured at her feet, and her husband, the love of her life, Captain Finn Murphy, has been left behind - two hundred years in the future. This was not the plan. But now that she's here, she might as well complete the mission. Find Maire Murphy and discover what trouble she's gotten them all into.
Finn Murphy thought he'd left his past behind, but his sister has gone missing. He watched in silence, unable to do anything, as his new bride was taken to the past by a man with no scruples. There's no question he'll follow. But how does one find someone in a time period when communication took weeks? And when the fog drops him in the middle of a rain-soaked field in France, his fears for AJ escalate.
Their only link-his sister Maire. Reconnecting with family is only the beginning. The discovery of an ancient journal-a diary-which speaks of time travel, brings new and old enemies together. How can AJ or Finn consider returning to the future when the secrets of time travel leave their fate in peril?