Library is a uncommon Land card from Ravnica: Clue Edition (CLU), collector number 18. Current market price: $0.36, TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {U} or {R}. {4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")