Walter and Peter in “Unfinished Business”

Walter

This time you have to make different choice. And if something goes wrong, Olivia would be available to...

Peter

Walter; Stop [hold back his tears] Olivia is dead.

Walter

But she won't be. Not there.

Peter

The machine? I turned that on 15 years ago.

Walter

And all the time I sat in prison, I couldn't figure out where it came from. I knew the pieces were buried millions of years ago, but how did they get there? So deep in the past. But now I understand. I sent them there. The hole in central park. I sent them back through time. Peter, you can stop the destruction before it occurs.

Peter

If that's the case, just don't send the machine back. They will never discover it and I'll never destroy the other universe.

Walter

No no no. Dosen't work that way. I have already done it. And I have no choice but to do it again.

Peter

Walter that doesn't make any sense.

Walter

It does. It is a paradox. I can't change what happens because it's already happened. But you can make a different choice within what happened. I simply need to find a way to bring your consciousness forward to now, so that you can witness what will happen if you make the same choice. Peter, for all I know, it can be happening already. Don't you see, we can fix everything. We can cheat the rules of time.

Peter

Imagine the repercussions.

Walter

It can't be worst than this. It can't be worst than this.