Sometimes before a test on Friday, Dorothy will say that her truck is broken. She will insist you go to your test, but just keep pressing "Help" and she will thank you. And then next Tuesday, you cant buy any card packs, but you will get a Miss Dorothy pack with very rare cards. I found a few Exodia Cards in these packs (Note: You will miss the Written Exam and Timed Duel if you help her, but it is ALWAYS worth it for the rare cards)