Superman/Batman #5, p.12

Elsewhen... Captain Atom flashes in and stumbles upon Future Superman.

Captain Atom: Where am I? WHEN am I?

Old Man Superman, with so much pain: Kansas.
Or what is left of it.
It doesn't really matter where you go on the planet-- it all looks like this...
...AFTER the asteroid...
I thought I could stop it...
Even traveled BACK IN TIME to change what happened...
Ironic, isn't it?
I left one planet as it exploded, only to have it destroy another...

Captain Atom, at a loss for words: I must've... QUANTUM LEAPED to this time period when MAJOR FORCE exploded.

Old mad Superman, in a moment of recognition: "Major Force."
Hard to remember... so long ago. Tokyo, wasn't it? I guess it doesn't matter.
Nothing matters anymore...

Captain Atom is in disbelief: There HAS to be a way to stop it.
The future isn't certain. It's FLUID.
I'M here...so that's PROOF that what you think you KNOW isn't set in stone.
The man I knew as SUPERMAN wouldn't give up.
AND YOU ARE STILL THAT MAN.

Last panel we see a a glimpse of that Superman still in Future Superman.