-THIS WILL CONTAIN SPOILERS FOR ENDGAME- The Avengers brought everyone back who was snapped away by Thanos, but they couldn't save two of their own. Natasha Romanoff sacrificed herself to get the Soul Stone on Vormir, a soul for a soul, the guardian had said. Tony Stark sacrificed himself to snap everyone back into existence, the power of the stones killing him. Now Steve Rogers and Clint Barton have to take the stones back to the exact moment they took them, restoring the timelines. This story WILL contain spoilers for Endgame, so read at your own risk!!!
12 parts