In a taut atmosphere, the Year 11 boys' ICT class is racing towards a deadline. Four weeks until half term; three big chunks of coursework to do; 25 minutes until the task in hand must be completed.
Clive Rosewell is looking down at the screen of his laptop, adjusting the display on the whiteboard. "3.05pm," he barks. "I want this done by 3.05."
Every moment of this two-hour lesson is tight, filled-up, urgent and full of energy. "Waqar, have you found that table yet?" "John, focus!" "Wesley, are you talking about work?" Every ounce of Mr Rosewell's considerable energy is focused on keeping the boys on task. When one puts up his hand to point out that someone is outside the door, he responds: "Well he'll have to come back later. I don't want you lot disturbed."
Earlier in their school careers, every one of these 20 boys was at risk of missing the target of five A-C grades at GCSE. And every one of them is now on target to pick up four of those five grades by passing GNVQ ICT.
Mr Rosewell, one of two deputy heads who teach this group four hours a week, is unashamed about the arguably controversial aim of the class, which is in its second year. "By giving them five A-Cs we give them the key to the next level," he says. "One of these boys wants to be a plumber. If he picks up one more GCSE he can go on and do his course. For that boy, who may have all sorts of difficulties in his life, that will make a huge difference."
In fact, the rationale behind the formation of the group is more complex than a desire to create a simple league table booster. Some of the worst-behaved boys in the year are not in the group - there's a delicate balance to be struck to ensure it doesn't become a "sink" set - and some boys are there because of learning difficulties rather than poor behaviour.
But putting some of the school's underachievers into a class taught by two of its most senior staff, Mr Rosewell argues, achieves several aims. The boys' results are likely to improve; the classes they are taken out of become easier to teach; and the boys get a taste of success, which helps build their confidence and improves their general attitude.
And, of course, the school's league table position will benefit. Last year, before the first boys' group completed its course, 8 per cent of Year 11 students at Seven Kings, a comprehensive in the London borough of Redbridge, were pushed through that five A-C barrier by the GNVQ ICT course. This year the figure could be even higher.
The lesson over, Mr Rosewell allows himself to pause for a moment in his airy ground-floor office. As deputy head, he divides his days between several distinct roles, which nevertheless dovetail neatly. The boys' ICT classes seem a natural extension of his wider responsibilities, which include overseeing key stage 4. They're also a smart fit with his other job, which is to analyse the school data to identify strengths and weaknesses.
A cursory glance at his office wall is enough to provide a map of his educational preoccupations. It's plastered with charts and tables. There's a register of Year 11 pupils at risk of underachieving, for instance - 49 out of 180, 15 of whom are in serious danger of failing.
Then there's the school's valued-added GCSE results. They present a glowing picture. January's national league tables put the school in the top 10 in England for value-added. But it also shows a target level well above where the school is now.
Mr Rosewell came here as assistant head five years ago. After starting out as a PE teacher, he says, he drifted into ICT after confessing at a job interview that he knew how to work a computer.
"I'm seen as the ICT person, but my background academically was on the humanities side," he says. "The way I approach it is to say that you can produce loads of data but if you don't use it you might as well not bother.
If you just highlight a problem, and say boys are underachieving, that's a waste of time."
Although behaviour at Seven Kings is generally good, he sees the targeting of distinct groups of pupils - such as the underachieving boys of Year 11 - as the way forward. Although boys at the school do less well than girls, the gap is smaller than the national average and staff hope the latest initiative will shrink it further.
"I'm acutely aware of disaffection," he says. "I remember from my own time at school boys who weren't engaged by what went on but who then went on to do good things. The biggest frustration for me is wasted opportunity."
So much so, indeed, that sometimes the pupils have to plead for mercy. "I told one of the boys in my Year 10 GNVQ class that I was determined to make sure he passed. He said, 'Can't I just be allowed to fail? Can't you just stop caring so much?"
Pupils' names have been changed