When Maggie Baxter was young, she met and fell in love with an American soldier named Jeremy who was about to be sent to the Korean War. He wrote her a letter promising to meet her when the war was over, but failed to include details of date, time and last name.
Unknown to Maggie, the Doctor's companion Steven was so moved by the story that he convinced the Doctor to travel into the past and let him inform Maggie that Jeremy had died in battle. However, Maggie didn't believe his story, and she continued to visit the meeting place every day. (PROSE: Waiting for Jeremy)