"It's fine," he said in the kind of cold, flat voice that only someone with serious Asperger's would take at face value.

Hannah's expression indicated to Nate that she did not suffer from Asperger's syndrome.

Nate looked away, a little repelled by the near panic he'd seen on her face. He was also afraid that if he looked at her, he'd feel bad and apologize, and he didn't want to feel bad or apologize. [...]