Batman: Return to Arkham - Arkham City

You will be able to rescue this hostage once you solve 160 riddles. See Genius for the Riddler Challenges guide. Go to the map location that appears after solving the Enigma Machine, break the question mark wall and enter.

This puzzle requires the line launcher, remote electrical charge and remote batarangs. Firstly, cross the body of water using the line launcher. The next part of the puzzle is to use the remote electrical charge to power an electromagnet, that will move a box above you. Move the box to block waterfalls and allow access to hit the switches ahead of you using the remote batarang.

In the next room, use the line launcher to pass through a turbine, then in mid-air, cross again through another turbine to your right.

The last room requires using the remote electrical charge to power an electromagnet. Use this electromagnet to move a box along a path, the end of which has a floor switch. Move the box onto the floor switch and rescue the hostage.

The hostage will give you new codes for your cryptographic sequencer. Use them, and solve 240 riddles for the next hostage (Intellectual).