Who is the Grinning Man, whos always grinning no matter what hes doing, even when hes murdering people, and what kind of deal did he make with Neron? Nightwing and the Titans better figure that out soon before they lose one of their team members

Then, in the backup, Nightwing continues his lessons mentoring Jon Kent, a.k.a. Superman, and this time its about using your detective skills instead of your fists.