You think we can still do something?

Lily here represents a remaining tie to reality for Stella. It's possible she will be able to change her sister's mind and prevent her from making the contract.

It is a curious case; but then, Stella's coming back and forth was curious in the first place.

So, Lily. You are the only one left with a chance of stopping her. Are you willing to go back underground? Even knowing the type of danger you will face down there?

(I suppose I could get caught in another earthquake. Or that voice would speak to me again. But it would be silly to have come all this way and give up now...)

(Besides, what would I tell people back in the real world? That my own sister ran away from me and won't come back?)

(They would draw their own conclusions. They'd think I'm not fit to take care of anyone.)

Of course I'll go.

Excellent.