Is plotting to set Dexter up? When they wee sitting outside with the drone, Harrison comes clean about his attack on the boy. He said something along the lines of "I set the whole thing up, almost as if I'm the hero."

This almost sounded like he was foreshadowing something.

I am likely wrong. I hope I'm wrong, as I like the direction the show is going. But they did say the ending would "break the internet". This ending would certainly do that. Dexter has been sloppy all season. Is it possible that the one time he actually let's his guard completely down (happened before, but not completely) it's his son that puts the nail in the coffin, so to speak?

Anyway, this is pretty unlikely but the "as above, so below" concept can be applied to this entire series.