Manhattan, New York.
Peter Parker and Harry Osborn stood back to back in their suits, facing their respective old enemies from after the Battle of New York, Doctor Octopus and Electro, along with two supervillains who had only recently appeared: Vulture and Shocker.
New York had truly suffered one disaster after another lately. After the alien invasion, criminals and foreign spies had flooded the city, all hoping to get a share of the equipment the aliens had left behind.
And just then, trouble had broken out within S.H.I.E.L.D. Hawkeye, Black Widow, and Captain America, the three superheroes directly affiliated with the agency, had all been recalled to Washington to deal with Hydra. Even after resolving the internal crisis, they had not had time to rest, instead pursuing the remnants who had slipped through the net.
During the operation, Steve Rogers had even encountered his old friend, James Buchanan Barnes, whom Hydra had brainwashed into the Winter Soldier.
After his surgery, Tony Stark had first helped S.H.I.E.L.D. locate the hidden Hydra agents, then shut himself in a laboratory with Bruce Banner to develop their Ultron system. Following the Hydra incident, both he and Dr. Banner believed that bringing Ultron into existence could no longer wait.
Meanwhile, after considerable effort, Thor had finally persuaded Odin to send him to Earth. But he had come to romance Jane Foster, with absolutely no intention of helping Earth deal with its criminals.
As Thor put it, Asgardians only dealt with threats from beyond Earth. Its internal conflicts were none of their business.
So although Avengers Tower stood in New York, the only ones actually still doing superhero work were Shining Locust and Spider-Man, two kids who had not even reached adulthood.
As for the new superhero team, the Fantastic Four, they could barely keep up