They Went This Way is a common Sorcery card from Murders at Karlov Manor (MKM), collector number 178. Current market price: $0.26 (foil $0.19), TCGplayer market prices via Scryfall.
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")