Pitiless Carnage

Every mass-sacrifice draw spell shares the same timing problem: the payoff only arrives after your board has done its work, and four mana is rarely lying around on the turn a wide attack has served its purpose or a dying engine hands you the window. Plot dissolves that friction by splitting when you pay from when you cast. Spend the cost on a quiet turn, exile the card, and it sits in a kind of layaway; later you cast it for free, and the mana you would have needed is freed for the rest of your plan. Both halves are sorcery-speed, so this is not a trick you hold up against removal or a wrath. It is a pre-scheduled unwind: you commit in advance to a turn when you would rather convert permanents into cards than keep them on the table. The sacrifice-then-draw ordering is where the reward lives, because the permanents you feed it can earn their keep on the way out (tokens whose job is finished, creatures with death triggers, anything that would rather die on your terms than an opponent's). The count scales with how much you are willing to dismantle, which makes this a payoff for go-wide boards and aristocrat engines rather than an even value trade, and Plot pays down almost the entire cost before the moment you actually need it.