You have a basic Mountain, Island or Swamp in library.
Steps
Play Maestros Theater.
Maestros Theater enters the battlefield, triggering itself and Stone-Seeder Hierophant.
Resolve the Stone-Seeder Hierophant trigger, untapping it.
Activate Stone-Seeder Hierophant by tapping it, untapping any land you control.
Resolve the Maestros Theater trigger, causing you to sacrifice it, then search your library for a basic Island, Swamp or Mountain card, put it onto the battlefield tapped, and gain 1 life.
The basic land enters the battlefield, triggering Stone-Seeder Hierophant, untapping Stone-Seeder Hierophant.
Activate Stone-Seeder Hierophant by tapping it, untapping Scaretiller.
Activate Scaretiller by tapping it, adding ({G} magic symbol) .
Scaretiller triggers, returning Maestros Theater from your graveyard to the battlefield tapped.
Repeat from step 2.
Results
Near-infinite landfall triggers.
Near-infinite lifegain.
Near-infinite lifegain triggers.
Near-infinite mana lands you control can produce.
Put all basic Islands, Mountains, and Swamps from your library onto the battlefield tapped.