How do you do this? Please don't just say Line Launcher. That two word answer isn't helping me out. Do I Line Launch right to the hostage, cause if so I suck and die every time. I've got 356 riddles and want to get this hostage out of the way before I get any more.
When you enter the room, the floor is electrified and you have a bar of death(BOD) moving around... Right next to you is a hackable panel (Conundrum) that will make part of the floor safe. Run along that path, ducking the BOD. then use a batarang on a ? light making the next section safe, follow it, climb up and jump the bridges gap. (Should be plenty of time, if not there is a safe spot or two you can use to trigger the ? again) The use the line launcher to head towards the glowing green lights in the back left corner. once their destroy the breakable wall, use the electromagnet to move the crate towards you then throw a remote batarang to hit the ? behind it. Run through the door that is now free of green lights. From here use the line launcher to cross the gap but be ready to re-fire it towards the hostage.
Hope that helps.
XBL:GT = pagrashtak Pokemon White FC 1463 5701 6173