Master Fu explains to Marinette his role as a Guardian of the Miraculouses; due to a mistake he made in the past, their temple was wiped out, and the Butterfly and Peacock Miraculouses were lost. He suspects whoever owned the Miraculous book must be Hawk Moth, sending Marinette into a panic at the thought it could be Adrien. Meanwhile, Gabriel grounds Adrien for stealing and losing the book. When Marinette learns the book was Gabriel's, she suspects he could be Hawk Moth instead. Hawk Moth unleashes an akuma, but de-transforms to his civilian self, Gabriel, and then akumatizes himself into The Collector, a supervillain who throws a book around to capture anything it touches into his pages. After Ladybug and Cat Noir eventually defeat him and revert him back to Gabriel, Master Fu is not so sure he is cleared of being Hawk Moth. Master Fu captures the contents of the book onto a smartphone, and Marinette returns the book to Gabriel, who reveals that he obtained the book during an overseas trip with his wife and that it is his last memento of her. He rescinds Adrien's grounding and shares a hug with him, and Adrien returns to school to the joy of his classmates. Gabriel returns to his secret lair and transforms into Hawk Moth, having fooled the heroes and vowing to get their Miraculouses.