Nightwing #103 cover a bruno redondo

Who is the Grinning Man, who's always grinning no matter what he's doing, even when he's 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 it's about using your detective skills instead of your fists.