The Library of Time Book 2 - The Library of Time, #2

Annie has been waiting for Sam's return from the 1300's for two entire months. He told her he would be gone one week, his focus on searching out his mother and finding out about the man who fathered him. When Annie finds a book in the stacks that contains the word HELP in large gold letters, she panics. Why didn't she remember that Sam has lost his magic and needs her to provide him a door to get home? She is now the one in charge of the Library of Time.  The door she conjures looks medieval, her trip into the past easy.
But when she reaches Sam she finds out that his reason for sending the message was only a fraught moment in time. He's happy where he is, fighting for Robert the Bruce in a long-ago war in Scotland. He says he loves her, but at the moment he has no interest in resuming their life in 2324. Annie is shocked by his attitude, but when she sees him with another woman it's the final straw. She has to leave.
But instead of taking her back to Edge in 2324, the door she conjures takes her to Sam's mother. Constance is in the same timeline as Sam, and is hugely pregnant. What Constance reveals pushes Annie over the edge. The baby she carries is Sam, and if the older Sam is killed in battle before the baby is born, Annie and Sam may never meet. And the chances of his survival are slim to none.