It will likely take modern neuroscience thirty to fifty years, he thinks, to either understand or replicate what happens to him when Molly smiles up at him. Even with so little real experience understanding human emotion, he can read certain things on her.

She's well-rested. She trusts him. She's happy, and not attempting to keep any secret worry from him. And she looks satisfied in a way he's never actually seen before--maybe to a lesser degree here and there in the past, but not this pleased.

(He knows, distantly, he must look sort of debauched himself. But he doesn't mind.)

"Good morning to you, too."