(Slagheap Valley isn't a spell.)
When Slagheap Valley enters the battlefield, sacrifice it unless you pay .
, : Scry 2.
: Add or to your mana pool.
Put Slagheap Valley on top of your library: Add to your mana pool.
.
, 
: Scry 2.: Add or 
to your mana pool. to your mana pool. 
