"Oliver Barrett/Atrbute" (2)
At the beginning of your upkeep, exile the top card of your library. You may play it this turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)
Once each turn, you may pay rather than pay the mana cost for a spell you cast from exile.
Gatherer works better in the Companion app!