After the angel Castiel takes her husband Jimmy as a vessel for a second time, Amelia Novak begins a search for him to reunite her family and chronicles her search in her diary. According to her daughter Claire, the diary is "mostly full of empty promises and regret", but Amelia writes about her meeting with Ronnie Cartwright who will take her to meet a "miracle man" shortly before she disappears for two years.
After Amelia is kidnapped by Tamiel, the diary along with her other things is left behind in her motel room. When Amelia fails to return, the motel manager sends her things to her last known address. Amelia's things bounce around a bit before finally ending up in Claire's possession in one of her foster homes.
When Claire begins her search for her mother, she uses Amelia's diary as a guide. She later tells Sam that while its "mostly full of empty promises and regret", there are enough clues within to give Claire a start on where to start searching. Using Amelia's last postcard, Claire is able to track the city she went to Tulsa, Oklahoma and the man she met with as Ronnie Cartwright. Claire meets with Ronnie who lies about not knowing Amelia, but slips up when he calls her by her full name. Claire later shows Sam the diary as they search for clues to Amelia's location and explains its history in her search.