Maybe there was no happily ever after [...] but there was happiness sometimes and she had it now, doing what she knew she was born for.

She realized all at once that Doon, thin, dark eyed Doon, with his troublesome temper and his terrible brown jacket, and his good heart---- was the person she knew better than anyone now. He was her best friend. --City of Ember--

A darkness different from Ember's, but just as frightening.

You know, son, I don't think there's such a thing as an easy life. There's always going to be hard work and there will always be misfortunes we can't control, lurking out at the edges - storms, sickness, wolves. But there is such a thing as a good life and I think that we have one here.

Poppy was now almost well. She still slept more than usual, but when she wasn't sleeping she tromped around the doctor's house pulling spoons off the table and spilling cups of water and crumpling pages of books. That is, she was almost her old self.

They lifted their faces to the astonishing warmth. The sky arched over them, a pale, clear blue. Lina felt as though a lid that had been on her all her life had been lifted off. Light and air rushed though her, making a song, like the songs of Ember, only it was a song of joy. She looked at Doon and saw that he was smiling and crying at the same time, and she realized that she was, too.

The main thing to do is pay attention. Pay close attention to everything, notice what no one else notices. Then you'll know what no one else knows, and that's always useful.