Fleeting Memories is a uncommon Enchantment card from Shadows over Innistrad (SOI), collector number 62. Current market price: $0.10 (foil $0.39), TCGplayer market prices via Scryfall.
When this enchantment enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you sacrifice a Clue, target player mills three cards.