Gone

"The people were gone, but their shadows remained" --Ray Bradbury (on his visit to Hiroshima after the bombing)

In which children became weapons, adults became monsters, and dreams became nightmares

Or, Damian Wayne, now nineteen and desperate to prove himself worthy of the title Batman to his aging father, goes to infiltrate the League of Shadows in order to investigate the whispers of yet another world-takeover plan. Instead, he discovers the ghosts of people long gone.

Sequel to "Left". Must read that first.