Eye of Erathis

When Eye of Erathis enters the battlefield,
search your library for an instant or sorcery
spell, reveal it, put it into your hand, then
shuffle your library.
At the beginning of your end step, look at the
top three cards of your library. Put one of those
cards into your hand, one on top of your library,
and one on the bottom of your library.
Unlimited Knowledge.