Eliminate the Impossible is a uncommon Instant card from Murders at Karlov Manor (MKM), collector number 54. Current market price: $0.13 (foil $0.06), TCGplayer market prices via Scryfall.
Investigate. Creatures your opponents control get -2/-0 until end of turn. If any of them are suspected, they're no longer suspected. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")