All of the Above

All of the Above is an achievement/trophy in The Missing Link DLC for Deus Ex: Human Revolution.

Towards the end of the game, when confronted with the choice to either save the prisoners or Dr. Kavanagh, choose neither at the console. Leave the central detention tower instead and look for a tall box on the lowest level on the outer ring. Moving the box will reveal a secret vent leading to the apparatus about to gas everyone. Destroy this infernal machine to earn the achievement.