The Library of Time Book 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...