This isn't a great story, so if you want to skip it for another day, I'd get it. It sucks having this kind of thing dumped in your lap the first day, and the shortest version of this usually makes more questions.
When Tor and I were little, Ultron and its armies wiped out the heroes, the villains, the civilians and military who fought with the heroes and villains against Ultron, people who had powers who weren't aligned with anyone - anyone it saw as a threat to resistance. Everyone fought hard, but they never got the victory that turned the war in their favor. Tony wasn't supposed to be the one who evacuated me and Torunn and the other kids, but his armor was damaged, so my dad ordered him to take us.
Everyone else died, or so Tony thought, except him, me, Tor, Azari, and Pym - and Vision, but we didn't know about Vision when we were kids. It wasn't until I was a teenager that we found out Francis was alive, his parents hadn't died that night, and there were other survivors, but even his dad was gone by the time we met Francis. Bruce was alive, but he lived in the desert. And Thor never came back after he dropped Tor off, so he wasn't around to fight Ultron.
But Ultron's gone. We stopped him before he'd subjugated the whole planet, so there was still part that wasn't totally trashed and rebuilt by the robots, and there were survivors all over that we discovered while we got rid of the robot armies. Humanity is harder to get rid of than Ultron ever predicted.