Mishra's Research Desk (The Brothers' War 162) - Uncommon

, , 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 (: 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.)