The Meerkat's Lair

I am in my bathroom. This bathroom is merged with the staircase of my school. Me and my friend have to hack some kind of system without anyone noticing. Students continuously walk down the stairs, and I sometimes look at them. Their faces are very clear. Using a fake card with multiple little numbers on its face I swipe in the door. This weakens the system allowing me to hack with a round, metallic device. I do this multiple times, until it triggers an alarm. Like in action movies, the lights turn red and flash violently. I swipe my card again and the sound intensifies. I can hear the teachers at my school getting closer. I grab my device and finish in time. Phew