Ongoing Investigation is a uncommon Enchantment card from Murders at Karlov Manor Commander (MKC), collector number 114. Current market price: $0.23, 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.