Mindcrafter's Safeguard

Draw a card, then exile up to one nonland
card from your hand. When you do, as long
as it remains exiled this way, it has
"{0}: Return this from exile to your hand.
Activate this only if you control lands equal
to or greater than this card's mana value."
In the court of the Sorcerer-King, secrets are the
greatest treasure of all.