Man Behind the Mask

You believe setting off the fire alarm would be the most suitable plan. At 2 in the afternoon, you ask your manager if you can use the bathroom. You are allowed so you head off toward the toilets immediately. Suddenly when everyone is out of sight you swerve in the other direction towards the fire alarm.

You look around to make sure no-one is watching and then pull the lever to trigger the alarm. Immediately, a screeching sound fills up the entire building. You see your colleagues getting up from their desks and start walking to the exit. What will you do now?