It was around 07:00 on a Monday morning. I had just started my shift in a large computer installation and was in the middle of the handover from the previous nights shift. It was at this time, same time, every week, the the fire alarms were tested. This involved inserting a key into the fire alarm control panel and manually sounding the alarms. Doing it this way meant that the local fire service wasn’t alerted so the they didn’t respond to a non-event.