sentences:  When Zim learns the Irkens are planning a new invasion called "Operation Impending Doom II", he, not understanding the purpose of his exile, "quits being banished" and leaves Foodcourtia and travels to the convention center planet called Conventia, for the Great Assigning, an event where Irken Elite soldiers are chosen to become Invaders and are then assigned by The Tallest to a planet.Invaders are soldiers whose missions are to blend in with the indigenous life forms of their assigned planet, collect information about the planet and its inhabitants and prepare the planet for conquest by the Irken Armada.Zim is determined to regain his status as an Invader and pleads with The Tallest to assign him a planet.