Are you suggesting they could want to take something-- perhaps a seed of mana-- from one of our worlds in order to solve their crisis? There is no guarantee that what we have struggled to achieve would be helpful to these people in any way. In fact, I'm surprised that whatever energy this city runs on doesn't react violently to the differing energies of the people living here.

[I feel like there should be some desk slapping here. Alas, wrong canon. We are not lawyers.]

Isn't it possible that there are cities besides this one? The city doesn't have the feel of being the last bastion of humanity, so there must be another reason why there is no communication from other parts of the world.