Some time in the game, you will recieve a call from Maggie Sawyer who will inform you of a stabbing that has happened. After you go to the given coordinates, you will find the victim there with Manhunter standing over the body. She tells you to scan the scene. You will find nothing but the wound, and you are told to stay alert for anymore victims. You will not be given their locations, and must find them like the side mission Identity Theft.
The next victim you find will give more clues. After scanning the wound you will find a poison, that was coated on the blade. It is revealed that this poison is extremely rare, and that if you can manage to find another victim that died through the same means, you can find where it is being stored.
The final victim you find will reveal the killers hideout. Squire will be there, saying she saw the victim stumbling and stuggling, and then collapsing. Scanning the victim will reveal the main stab wound but also a large number of scratches. The body contains a high amount of the poison, and through this it is realized who the killer is, Jade Nguyen, or Cheshire.
After going to the coordinates found you will arrive at a small, almost shed like building. After entering you will find a large amount of the poison. As you walk forward, you will trip over a wire. A grate will fall down and you will be trapped. Cheshire reveals herself, and leaves, with a smug "Bye Batman".
To escape, just simply use the Cryptographic Sequencer and hack the panel. The mission will be over.
- The fact that she escaped indicates that she may have a role in Batman: The Institution.