Chrom: Where.. is this place? Since when did we...
Naga: .....
Chrom: !? You're...!?
Naga: I have been waiting, warriors from the other world. I am the one who called you here.
Chrom: What...?
Naga: There is a world that will soon be at its end... however, I myself am not able to save that world... the only ones who can save that world are ones who can jump across different worlds and time itself — in other words, only you...
Chrom: A world that only we can save...? Does such a world exist?
Naga: Yes... that world will be devastated by the revival of the ancient evil dragon. The only hope... are twelve children, including the holy princess who hides the power to change destiny. ... however, at this rate, they will all die.
Chrom: The children who will bring hope... will die?
Naga: Yes... the four who hold the blue and scarlet Gemstones will be annihilated without bringing them back. The four who hold white and black Gemstones will also be annihilated, with their homeland right before their eyes. The three who hold the green Gemstone and the pedestal will barely return back to reunite with the princess waiting in her country... however, immediately after that, they will be killed along with the princess.
Chrom: And then, that world...!
Naga: The only thing waiting for a world that has lost all its hope is a future dyed black with destruction. That is the state of that world. A destiny that can't be changed. You should really only follow this destiny that has been set in stone without interfering. However, that is much too cruel... so I will ask for your help... Please... please, somehow do something to save that world and change its destiny...
Chrom: ... we help the troubled. Even if they happen to be in another world, that doesn't change. If there's someone who can be saved with our hands, there's no way we can ignore them. If they're fated to perish if we don't save them... even more so.
Naga: ... thank you, warriors from another world. Now then, I will send you to that ending world right now. First, please save those four children who are holding the blue and scarlet Gemstones...
Chrom: I got it.
Naga: I leave you with one warning... the world you will be sent to is a world a lot like your own. You may meet ones who hold the same existence as your precious people... if you would like to encourage them, please fight alongside them closely. ... now then, I believe in you. Please... change that world's fate.

Lucina: This place is — no...!
Chrom: What's wrong, Lucina?
Lucina: This feeling... it's the same... it's the same as the future of despair I came from...!
Chrom: What...!? Are you sure!?
Lucina: There is no way I would forget... this suffocating, unpleasant air is the same air I had felt long ago. However, if this is similar to that future, then there is no guarantee that everybody will be able to come home alive...! To bring Father and everyone else to this kind of world of all places... this... this is...!
Chrom: Lucina, calm down. ... I'm glad that I was able to come to this place.
Lucina: !? W-what are you saying, Father!? ... you might die, you know!?
Chrom: Yeah... but you survived such a world where you could've died, and came to us to change our future, right?
Lucina: That's...
Chrom: Then I want to save this world too... even if there's a possiblity of me dying. The Chrom in your future couldn't do anything for you all. But this is different. This time, I can save you in this future. Even if you may be a different person, there is no way I could abandon you. I want to save... this world's you, as well as your comrades.
Lucina: But... what if you die again, Father!?
Chrom: ... don't worry. I don't be defeated here. After we help this world, we'll need to save our own world next, after all. Until then, I definitely won't die.
Lucina: Father...
Chrom: Believe in me, Lucina. I would never lie to you.
Lucina: ... I understand, Father. In that case, I have a request as well. Please... save our other selves of this world.
Chrom: Yeah! We'll see this through!