@Branthog: The hostages are on the 2nd floor in Assembly Room #1. There are two paths:
- The Door. But it's a Deux Ex game so it's never the recommended way. As soon as you enter, you trip the bomb and only have 30 secs to hack it before everyone in the room dies.
- The Vent - aka where you'll spend all your time. The one you're looking for is on the first floor to the right, just as you enter the Assembly room. It leads you all the way to the hostage room and allows you to hack the bomb without a timer and free the hostages. You also get subsequent missions from one of the hostages if you succeed.