When new threats begin to exceed the Avengers’ usual scale, Captain America and Iron Man decide to greatly expand the team so it can respond wherever the balance of the world is at risk. Their battles bring them into conflict with the Builders, cosmic wars, and phenomena capable of altering the very structure of the universe. At the same time, the Illuminati secretly search for a way to stop incursions between different realities, even if it means making increasingly dangerous decisions. Gradually, the two storylines converge toward a multiversal crisis in which the Avengers must confront the limits of their power, their alliances, and their convictions.