Outstanding Intellect

Look at the top four cards of your library,
you may reveal one of them and put it into
your hand. If you do, counter target spell
unless your opponent pays {x} where X is
the converted mana cost of that card. Put
all other cards revealed this way onto the
bottom of your library in any order.
"I read about it, in Hogwarts; a History"
- Hermione Granger