Activate Mystic Sanctuary and Lavabrink Floodgates by tapping them, adding 2.
Cast Ghostly Flicker either from your hand or from the top of your library by paying 2, blinking Mystic Sanctuary and Lavabrink Floodgates.
When Mystic Sanctuary enters untapped, it triggers, putting Ghostly Flicker from your graveyard onto the top of your library.
Repeat.
This ingenious loop is powered by Magus of the Future, which lets you cast spells straight from the top of your library while keeping your options transparent. You begin by tapping Mystic Sanctuary and Lavabrink Floodgates for mana, then use those resources to cast Ghostly Flicker. By targeting both lands with the spell, they re-enter the battlefield; Mystic Sanctuary's triggered ability places Ghostly Flicker right back on top of your library, and Lavabrink Floodgates refreshes for its mana once again, setting the stage for an endless loop.