Hidden Courtyard

Every white source that enters tapped already charges you tempo for its color; this one charges more of that toll up front and refunds it in the endgame instead. It never touches any color but white, and it comes down slow, so through the opening turns it does the least glamorous work in Magic: a tapland. The payoff is entombed in the sacrifice line. Five mana and the land itself convert a spent white source into a sorcery-speed Discover 4, digging until it hits a cheap nonland card and either casting it for free or tucking it away for later. That is the entire bargain. The design's real cleverness is where it puts the card advantage: not in a nonland slot the deck has to justify, but inside a land, so the manabase carries its own flood insurance. When the extra land off the top would otherwise be a dead draw, this one cashes itself in for a live card and frequently a free spell. Discover is what makes the trade honest: no promise of a specific answer, but a guarantee of hitting something, with the free-cast clause turning a slow fixing land into a genuine mana sink once your other lands have stopped mattering. It is a land that agrees to be a bad topdeck early in exchange for never being a bad topdeck late.