Gateway of Secrets

{x}{t} Search you library for a card with converted
mana cost X, exile that card face down, until end
of turn you may cast that spell without paying
it's mana cost.
At the beginning of your end step you may put
any number of cards exiled with Gateway of
Secrets into your graveyard, then you draw 2
cards for each card put into your graveyard this
way.