Dimir Machinations is a uncommon Sorcery card from Ravnica: City of Guilds (RAV), collector number 84. Current market price: $1.31 (foil $5.99), TCGplayer market prices via Scryfall.
Look at the top three cards of target player's library. Exile any number of those cards, then put the rest back in any order. Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)