Mishra's Research Desk is a uncommon Artifact card from The Brothers' War (BRO), collector number 162. Current market price: $0.22 (foil $0.25), TCGplayer market prices via Scryfall.
{1}, {T}, Sacrifice this artifact: Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card. Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)