User blog comment:Hermione Chase/"The Blood of Olympus" Expectations/@comment-4780373-20131015193422/@comment-24205801-20131018223204

I think Thalico happened because before HoH, neither of them had had any love interests of any sort (while pretty much every main character has). Combine that with both being children of Big Three gods, dark, and loner-types, and you get a new power couple.