What are the abilities of Mishra's Research Desk?
user
{1}, {T}, Sacrifice Mishra's Research Desk: Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.\nUnearth {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.)
assistant