"I wouldn't guess one of the parents did it," she says thoughtfully. "Because that wouldn't explain why the mom was relieved, even if she really, really didn't like him or something, she would've had to have been worried they'd get caught unless it was the dad that did it and she didn't even know, but that seems unlikely. The ransom theory has the same problem, but less of it. Driven away by bad treatment explains why the mom was relieved, though, if she wasn't the one treating him badly but wasn't brave enough to do anything about it herself."