Volcanic Lake

Hideaway (This land enters the battlefield tapped.
When it does, look at the top four cards of your library,
exile one face down, then put the rest on the bottom of
your library.)
{t}, Pay 1 life: Add {u} or {r} to your mana pool.
{u/r}, {t}: You may play the exiled card without
paying it's mana cost if you've cast three other
spells this turn.