Level 27 at 02:15

Treat it as real until it is proved otherwise. Three false alarms on the same loop is a reason to distrust the sensor, not a reason to ignore a second, different signal in the same zone - the sprinkler flow switch fault means the picture is not simply 'the usual fault'.

First five minutes:

1. Call 999 and ask for the Fire Services Department. Say the address, the floor, the panel indications, and that two cleaners are on level 30. Do this before investigating. A guard who 'checks first' is the classic cause of a delayed response.
2. Let the alarm sound. Do not silence the sounder and do not reset the panel. Silencing removes the warning for anyone else in the building.
3. Account for the cleaners. Call them, tell them to use the fire staircase, not the lifts, and to go to the assembly point. Confirm they are out. They are the only known life risk.
4. Go up only if it is safe and never alone if avoidable. Use the fire staircase, take a radio and a key, and turn back at the first sign of smoke. You have no breathing apparatus and no firefighting training; your job is confirmation and information for the FSD, not firefighting.
5. Keep the fire command centre manned and the line free for the FSD and for the cleaners.

What you must not do: take a lift to 27, break glass or force doors on a smoke-filled floor, or assume 'false alarm' because the log says so.

It does not cancel the fire response, but it changes where you stand.

The holdall is an unattended item in a building with no occupants other than two cleaners 30 floors up. It has been there ten minutes with no owner. You do not open it, you do not move it, you do not put it in lost property, and you do not use a radio or mobile phone right next to it - keep transmissions at a distance.

Sequence:

• Move your post outside the lobby and keep the entrance clear. The FSD crew needs the approach, the lobby and the panel, and they must not walk into an unmarked bag at the door.
• Cordon the sofa area with what you have - barriers, a rope, chairs - so nobody drifts near it, and note the exact time you first saw it and its description.
• Tell the 999 operator about the bag in the same call or a second one, and tell the arriving FSD crew and any police officer before they enter.
• Start an evacuation of the ground floor and any occupied areas in the normal way, using the assembly point, not the lobby.

Why this order. The known life risk is the cleaners on 30; the bag is a possible hazard at your own post. You cannot investigate both, so you remove yourself from the hazard, keep the building's emergency response working, and hand the information to the services that can act on it.

Log, with times to the minute: the panel indications and zone numbers at 02:15; the three previous false alarms and the technician's 'monitor' note (cross-referenced, not rewritten); the time of the 999 call and the reference; the time the cleaners were contacted and confirmed out; the time and route of your own investigation, or the reason you did not go; the first sighting and description of the holdall; the cordon; the FSD arrival and the officer in charge; any silencing or reset, by whom and on whose authority; and the supervisor's non-response.

Mistakes being tested:

• Silencing or resetting the panel to stop the noise - that is the single most damaging decision available to you.
• Deciding it is a false alarm from history rather than from a verified check.
• Delaying the 999 call to investigate personally, or phoning the supervisor first when the supervisor does not answer.
• Forgetting the cleaners. A building 'empty' at 02:15 usually is not.
• Leaving the bag in place without cordoning while you go upstairs, so the FSD walks into it.
• Going alone and using a lift.

The wider point. A repeated fault in the log is evidence, not an excuse. If the fault was reported and nothing was done, the log is also the record that protects you - which is why the entry must be factual, timed and written at the time, not reconstructed the next morning.