To unlock this mission you have to chose the above spoiler when talking to Markus as Connor.
You'll have two fight scenes before getting to the bottom level. During the loft sequence immitate the guard, DO NOT USE YOUR OWN VOICE.
This is where you'll need to know about Hank's Son (which you'll know about if you've picked up every Hank clue along the way), Once you completed tbe fight scene/silly No it's him bollocks. You'll free the Androids.
NOTE: This unlocks upon completion of the game and not after this specific scene.