Strange can't count the number of attempts he wasted on trying to get Quill's plan to work.
It was a good plan. It offered a good chance. And in a thousand universes it got emso close./em He tried again and again to push it over the edge. To find the one way to turn that almost into victory.
But something always went wrong. Mantis failed to hold him long enough. Quill lashed out in his fury over Gamora. They couldn't anchor Thanos well enough. Something.
Eventually he gave up and moved on to other paths, but none of the others even came that close.
So he returned to it again and turned the problem over carefully. He let it play out this time. They failed to retrieve the gauntlet. Fine. Then what happened?
The fight after it also showed promise. He wasted more time trying to get that promise to turn into victory.
Nothing.
Nothing but bitter failure.
Thanos killed Stark in most of those scenarios. Unfortunate, but an acceptable loss.
And the kid.
He gritted his teeth and let it keep playing.
They all died. All except him. Him, Thanos kept alive.
He was, after all, the only one who knew where the time stone was.
Strange couldn't see a reality where he didn't eventually break.
What if . . . What if he gave up the stone with a trick, a trap of some sort? He could frame it as a bargain, Thanos would buy that, it was the sort of stupid thing heroes did, and then -
But Thanos sensed the trap. Every time.
In utter frustration, he watched the rest of it play out. Maybe seeing half the universe die would help his motivation.
And - oh. There. A regret, preying on him, weakening him, tempting him to return in time to a point where he was much less powerful than he was now.
They could not defeat Thanos.
But if they gave Thanos enough power, he would defeat himself.
"Thanos, I have come to bargain," he whispered, and then he let the visions end and looked up at those who, like him, would be meeting death shortly.