According to the map, the hostage should be right where I'm standing. I'm on the street directly south of the church/med center and there is a building near the wall of the Restricted Area with a green ? painted on the wall. The hostage, again according to the locator on the map, should be directly in front of the ? painted on the wall.
I've beaten up the crew on the street and interrogated the Riddler's henchman, and now there's nothing here ... at all. Did my game glitch, or am I missing something obvious?