These are the stories of the end of the world, and the people who faced the end together. Some wore costumes, some didn't. Some had powers, and all some had were each other. They were the Mighty Avengers. And this is the story of their last day. Then, in the Battleworld futuropolis of Mondo-City One, Boss Cage is the law! But when the fascist fiefdom annexes neighboring Yinsen City, who'll defend Ho Yinsen's dream of peace? The Mighty Defenders! As Captain Britain faces Boss Cage from the inside of a cell, Mondo-City breaks out its biggest gun. Can even the Defenders stand against the multi-story murder-dozer called War Machine? Plus: The Age of Ultron hits the UK! Collecting CAPTAIN AMERICA & THE MIGHTY AVENGERS #8-9, CAPTAIN BRITAIN & THE MIGHTY DEFENDERS #1-2 and AVENGERS ASSEMBLE (2012) #15AU.