Out Cold is a common Instant card from Murders at Karlov Manor (MKM), collector number 66. Current market price: $0.26 (foil $0.14), TCGplayer market prices via Scryfall.
This spell can't be countered. (This includes by the ward ability.) Tap up to two target creatures and put a stun counter on each of them. Investigate. (If a permanent with a stun counter would become untapped, remove one from it instead.)