Thwart

Hard counters are priced in mana you spend on the opponent's turn; this one offers a second ledger entirely, paid in Islands already sitting in play. Bounce three of them and the spell resolves for free, every mana left untapped and no extra card discarded. That is the trade the free-spell pitch cards made famous: convert a resource you hold in surplus into one you are husbanding for your own plays. The blue-on-blue version of that bargain is keyed specifically to lands with the Island type rather than generic permanents or cards in hand, which is both the constraint that pays for the free counter and a confession about the deck it wants to live in. A mostly-blue board of six or seven lands can absorb the bounce on a defensive turn and rebuild from it over the next several. The cost is real, just deferred: it sets development back, leaves the board exposed to whatever resolves after, and demands land drops made all over again. But on the turn that decides a game, when the opponent finally commits the spell they cannot afford to lose, answering it without touching the mana pool is a tempo swing no four-mana counter can match. The math of the late game tilts whenever a counterspell stops costing the resource you most need for your own clock.