Molten Note is a uncommon Sorcery card from Secrets of Strixhaven (SOS), collector number 204. Current market price: $0.16 (foil $0.23), TCGplayer market prices via Scryfall.
Molten Note deals damage to target creature equal to the amount of mana spent to cast this spell. Untap all creatures you control. Flashback {6}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)