Marauder's Map

My family is Potter-obsessed. We regularly quiz each other on super obscure Harry Potter facts. My sister and I made a list of our most difficult trivia questions and turned it into an Alexa skill.

An Amazon review:

"I listen to the Harry Potter books almost every [single] night before I go to bed. I re-read them every year, and I have an annual club meeting with people who legit test on this stuff. This is hard. VERY hard. If you are a FANATIC like me, this is what you are looking for. If you read the books occasionally, this isn't for you. It asks for page numbers, obscure names, potion ingredients, spells only used once. It is very hard, and loads of fun. LOADS. I spent hours doing this alone."