Satisfactory answer

After spending a few days in the little villa, the three of them went down to the Underground City again.

This time, they had a purpose.

Many women below might have gotten used to this kind of life, but there must still be those who disliked this way of living, who yearned for the life on the surface.

What they needed to do was to help these women who wanted to get out.

To take them up to the surface.

Perhaps they would die as soon as they got out, perhaps life above would be very hard, far less comfortable than the one underground.

But every person should have the right to choose.

To be honest, this was kind of foolish.

Only the three of them had the time to do this kind of thing.

This kind of trivial pursuit, in most people's eyes, was useless, even superfluous.

The women who wanted to leave were, in fact, easy to find.

All you had to do was look into their eyes.

The eyes of those who wanted to stay, and those who wanted to leave, were different.