Where is the Cryptographic Sequencer on Batman Game?

My boyfriend is annoying me to death.. can anyone help him find where he can find the Cryptographic Sequencer for Batman on Xbox 360? i have seen various posts of how to use it but none to actually state where to find it?!|||You get the Sequencer from the Warden after you rescue him later in the game.|||lol. first off tell him to put down the controller and spend some time with you. the cryptographc sequencer is one of the last gadgets he will get in the game, and comes through natural story progression. it is a cannot miss item so don't worry about it, he will get it.