Mishra's Factory [Fourth Edition (Foreign White Border)]Set: Fourth Edition (Foreign White Border) Rarity: Uncommon T: Add 1 colorless mana to your mana pool. 1: Mishra's Factory becomes an Assembly Worker, a 2 2 artifact creature, until end of turn. Assembly Worker still counts as a land but cannot be tapped for mana the turn it comes into play. T: Target Assembly Worker gets +1 +1 until end of turn.