Ongoing Investigation is a uncommon Enchantment card from Shadows over Innistrad (SOI), collector number 77. Current market price: $0.26 (foil $0.36), TCGplayer market prices via Scryfall.
Whenever one or more creatures you control deal combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") {1}{G}, Exile a creature card from your graveyard: Investigate. You gain 2 life.