I'm kind of surprised in how fast Will Graham was able to 'crack' the mystery of Abigail dark secret in that she killed that one kid. But what's even more surprising is that Hannibal admitted to cover up and burying the body for her to "protect" her future. That's a pretty big assumption on his part that Graham would keep it a secret from Jack Crawford. The flashback scene at the very end with Abigail was interesting in that we get to see how she was complicit to her fathers crimes.