What great discovery does Equality make in chapter 10?

He finds a two story glass house with a flat roof. This is something they've never seen before.

Description of the house;

Both Equality 7-2521 and Liberty 5-3000 know the house is from the Unmentionable Times. But neither of them is afraid. So they go in.

Equality 7-2521 is surprised to find that the rooms are small. Not more than a dozen people could have lived in the house. He's also surprised to see how full of light the rooms are. And that they seem to have lots of glass, which isn't quite glass, but reflects his image back to him.

Equality 7-2521 finds the only bedroom, and is astonished to realize that the house was meant for only two people.

There's also a library in the house, with lots of manuscripts "of a strange shape." Sounds like books.

Equality 7-2521 proclaims to Liberty 5-3000 that they shall never leave the house, nor share it with anyone else. It's theirs alone. Liberty 5-3000 responds, "Your will be done" (10.16).

Equality 7-2521 goes to gather wood, and kill a mountain goat for food. Liberty 5-3000 spends the whole day staring at herself in the mirror.

When the sun sets, Liberty 5-3000 falls asleep on the floor in the midst of a whole horde of clothes and pretty trinkets she's gathered. Equality 7-2521 carries her to bed, then goes to the library and starts to go through the books by candlelight.

Equality 7-2521 looks at the sky and the mountains and feels as if the world still has great secrets and gifts to reveal to him. What secrets is the world still holding from him?