Meanwhile, Aragorn and the others have plenty to do. There is a giant battle being waged at Minas Tirith. The whole of Gondor is trying to protect the city. However, a giant company of orcs, wild men, and a variety of creatures has gathered outside the walls and are waging war. The steward of Gondor is not at all pleased to have Aragorn return. He does not want to be replaced as the leader. Eventually the steward goes insane, and Gandalf takes charge. It is not looking good for Gondor. Aragorn is not with them at the battle. He has taken an ancient path and has to seek the loyalty of a host of ghosts who had betrayed an ancestor of Aragorn's. He tells them he will set them free if they will help with this battle. He wins their allegiance and brings them to Minis Tirith. With their help they can win the battle.
However, the fate of the world still rests on whether or not Sam and Frodo can destroy the ring in Mt. Doom.