THERE is a glint of fear in David Miliband's eyes as he walks across the playground towards the exam hall.
It is the first time the school standards minister has returned to Haverstock secondary in Camden, north London, since he took his A-levels there 20 years ago - and got a D in physics.
"It's pretty odd really," the minister mutters. "You always feel trepidation in a place where you were a student, even when you are in authority." With him is Nikki Haydon, an English teacher at Haverstock who remembers Mr Miliband as a bright teenager who gained a place at Oxford.
"He kept his head down and was hard-working," she said. "I wouldn't say he was a swot, but..."
"I was a bit square," Mr Miliband interjects. The 37-year-old is shy about revealing how he did in all his exams, but says he has happy memories of studying further maths because it meant he could attend classes at Camden school for girls.
The visit was part of a nostalgic day for the minister. Earlier that day he visited Carlton primary school, also in the borough, where he was a governor for three years.
The multicultural school was struggling when Mr Miliband gave his services, but has made radical advances in the seven years since he left. It recently received a glowing inspectors' report and appeared on this year's chief inspector's list of the most improved primaries.
The minister said: "I can't take any credit for the work here. But we, erm, laid the foundations."
Changes since his departure include extensive refurbishment, and more stress on managing behaviour and supporting children with special needs.
The school also has a multi-sensory room, where pupils can experience different textures and coloured light.
Gunnar Pettersson, a current governor, said that Mr Miliband had been highly active, particularly in improving the school's toilets. "For someone who is a born politician, he spent a lot of time coming into the school and reading to the children," he said.
"At governors' meetings he was always getting us to focus on the teaching and learning whenever we strayed on to other issues. He was not just here for his CV."
At the time, Mr Miliband was head of the policy office for the then opposition leader Tony Blair. He left the school to work in Downing Street when Labour came to power.
At Haverstock, Mr Miliband cannot stop saying "Fab!" as teachers describe plans to rebuild the secondary in a pound;20 million private finance initiative, which will create three football pitches on the site.
The minister said that even as a schoolboy he had been keen to understand the "challenges of inner-city education" - suggesting the young Miliband was already plotting a political career. But pupils on the school council at Carlton learned he once had another ambition - to be a bus conductor.