Muddle the Mixture is a common Instant card from The List (PLST), collector number RAV-60. Current market price: $2.04, TCGplayer market prices via Scryfall.
Counter target instant or sorcery spell. Transmute {1}{U}{U} ({1}{U}{U}, 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.)