Case of the Crimson Pulse is a rare Enchantment — Case card from Murders at Karlov Manor Promos (PMKM), collector number 114p. Current market price: $0.84 (foil $0.99), TCGplayer market prices via Scryfall.
When this Case enters, discard a card, then draw two cards. To solve — You have no cards in hand. (If unsolved, solve at the beginning of your end step.) Solved — At the beginning of your upkeep, discard your hand, then draw two cards.