Zsasz's Hideout

Zsasz's Hideout is located in the Industrial District. The hideout was where Victor Zsasz made his phone calls. Batman traced his calls after he found several phones scattered across the mega-prison, and used the Batcomputer to locate and capture Zsasz.

Arkham City Incident
Victor Zsasz kidnapped three Political Prisoners in Arkham City. He threatened to kill them unless Batman could answer a ringing phone, race across Arkham City, and then pick up another ringing phone.

Zsasz mentioned to the dark hero that he had a friend who had assisted him in bouncing the signal from his hideout to Bludhaven, and made it difficult for Batman to trace him.

Zsasz repeated that process until Batman was able to break through his encrypted signal and tracked him down to an abandoned building in the Industrial District. Batman then had to navigate through the building in order to get closer to Zsasz. But as Batman made his way through, Zsasz attempted to make another call.

Once Zsasz was taken down, Batman locked him up in his own control center and let the remaining two prisoners free. The prisoner that Zsasz killed remained beneath the water near the floating bridge, and was only visible in Detective Mode.

Trivia

 * The Broker sold the building to Zsasz sometime before the events of the game.
 * To the left of the control panel, a Joker Card could be seen amid a slew of papers bearing the Pinkney letterhead.