Bruce Banner and the Ancient One Explain Infinity Stones and Time Travel

Thanos's potential for mayhem made itself visible very early.

And you did nothing?

If I acted preemptively to curtail potential misbehavior, Dr. Banner, your gamma shenanigans would have ended on a grad school blackboard.

Would you prefer I had? No. Good answer.

You win one Infinity Stone.

Of course, there will be consequences.

Yes.

If we take the stones, we alter time, and we'll totally screw up our present day even worse than it already is.

If you travel to the past from your present, then that past becomes your future, and your former present becomes the past.

Therefore, it cannot be altered by your new future.

Then all of this is for nothing. No. No, no. Not exactly.

If someone dies, they will always die. Death is irreversible, but Thanos is not.

Those you've lost are not dead. They've been willed out of existence, which means they can be willed back, but it doesn't come cheap.

The Infinity Stones bind the universe together, creating what you experience as the flow of time.

When you remove one of these stones, this flow splits.

Your timeline might benefit, but my new one would definitely not.

For every stone that you remove, you create new, very vulnerable timelines.

Millions will suffer. Then we can't take the stones.

Yet your world depends on it.

Okay. What if...

What if once we're done, we come back and we return the stones?

Well, then the branches would be clipped and the timelines restored.

Easy-peasy lemon squeezy. You're a very interesting person.

It's quite a burden.

Be warned, Bruce. Power is only useful when it's used, but using it might mean giving it away.

I promise we will return the stones. I don't mean just the stones.