The morning after an exhausting parents' evening, Gavin Bellamy was tired but proud. He would shortly be heading to a full staff briefing at which he planned to thank his colleagues at Norwich's Sewell Park College for their hard work the previous day.
But, unexpectedly, Mr Bellamy was interrupted by a colleague. There was an urgent phone call for him. It was a conversation that would set his heart racing and force him to tear up his briefing notes: Ofsted was coming. And the inspectors would be arriving in 10 minutes.
"The first thing that went through my mind was: 'That's not possible.' I didn't have time to be fearful," the headteacher told TES.
As the massed ranks of teachers gathered for a staff meeting, they could not have guessed the bombshell that Mr Bellamy would soon announce.
"There were some shocked faces. I think some people thought it might have been an attempt at humour on my part," Mr Bellamy said.
But it was no laughing matter. As part of its crackdown on satisfactory schools with issues surrounding pupil behaviour, Ofsted has launched a campaign of no-notice, one-day inspections. And Sewell Park was first in the firing line.
For Mr Bellamy, who only took on the job - his first headship - six months ago, it was a daunting task. Sewell Park had been rated satisfactory for pupil behaviour in 2010, and the pressure was on to convince the inspectors that the school was heading in the right direction.
In its last full inspection in June 2010, it was ordered to overhaul its behaviour policies within six months, ensure that internally excluded pupils were using appropriate programmes of work within 12 months, and raise attainment to at least the national average within two years.
And the school seems to be rising to the challenge. Following the no-notice inspection, the school was rated good for making improvements, its capacity for sustained improvement and, most pleasing of all, for its effectiveness in improving pupils' behaviour.
Standards, although still below the national average, are "rising steadily and sustainably", with "attainment on a strong trajectory of improvement for 2012 and beyond".
"The staff responded magnificently. Ofsted said we had a good capacity for continued improvement, and could get 'good' next time (the school has a full inspection)," Mr Bellamy said.
Sewell Park was six weeks into the implementation of the Behave to Achieve system, a consequences-based approach to discipline that Mr Bellamy had learnt about while working under "superhead" Sir Dexter Hutt, who recently retired as executive leader of Hastings Federation of Schools.
"The inspectors were totally blown away by the impact it had in such a short period of time," Mr Bellamy said.
As a result, the headteacher said the inspection was a positive process, and allowed inspectors to get an accurate snapshot of the school. "I was very reassured that it went so smoothly," he said. "It's really helped to raise the confidence of the staff."
After all the panic and worry about Ofsted inspectors swooping in for unannounced "dawn raids", it seems that - in the experience of one school, at least - no-notice inspections are perhaps not that bad.
What Ofsted said about behaviour at Sewell Park College:
Full inspection, June 2010
The school recognises that it needs to improve the management of poor behaviour - a concern of parents and carers and staff. It is inconsistent and not well implemented across the school.
No-notice section 8 inspection, October 2011
Expectations about punctuality, attendance, behaviour and participation in lessons have been clarified so that students are in no doubt about what is acceptable and are aware of the consequences of transgression ... Procedures for dealing with misdemeanours are unequivocal and serve as a suitable deterrent.