Into the Pit 
Enchantment
You may look at the top card of your library any time. You may cast spells from the top of your library by sacrificing a nonland permanent in addition to paying their other costs.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL