Remus celebrates his twelfth birthday with heartfelt surprises from his friends, including a chaotic triple chorus of “Happy Birthday” and a homemade four-flavor cake. The biggest reveal comes when he shyly unveils his secret Hogwarts project — a detailed, moving map of the castle he’s been crafting alone. James, Sirius, and Peter are immediately captivated, jokingly dubbing it the Marauder’s Map, planting the seeds of their future legacy. Though Remus hesitates about its ethical use, he starts to realize how powerful their shared magic could become.