Uncontrolled Infestation

Land destruction priced for a single nonbasic, and aimed at the most predictable behavior a land has: getting tapped for mana. The trap closes the instant the enchanted land is used, which means the owner can keep it as a do-nothing permanent forever or sacrifice the destruction by tapping it once. That choice is the whole bargain, and it is a worse bargain than it looks, because a dual land or a creature-land or a value land that the controller is content to leave untapped costs them nothing to ignore. Compared to the Stone Rain school of land destruction, which simply removes the land and the decision, this hands the opponent an out: don't tap it. The design lives or dies on whether the target is a land the opponent cannot afford to leave dormant, which narrows the pool to manlands, mana-fixing the opponent is starved for, or symmetrical lands feeding a combo. It is a sharper, cheaper tool than blunt destruction in exactly the spots where the opponent has no spare land to spend the turn untapped, and dead weight everywhere else. The flavor reading is clean: an infestation that punishes use rather than mere existence, dormant until the land does its job and then collapsing it.