Ellis's perspective on scouting is borderline spiritual. She thinks she's good at it because her dyslexia made her focus on visual stuff. She believes in scout karma. 'If you're meant to find that girl on that day, you will,' she says. 'I don't lose sleep over the girls I don't get.' Nonetheless, she will make a concerted effort to track people down when necessary. 'I saw this great boy yesterday, walking along the road. I was late for a meeting, and I thought, shall I stop? But I couldn't, I was too late already. He was near the school that my daughter goes to. A gorgeous black boy with an afro. And it was 8.29, I looked at the clock. I thought, that must be the time he goes to school. I'll go back then until I see him again.'
Bolstering the ranks of the random street finds are the spoils of the increasingly popular free-for-all, pre-arranged scouting event. Your Clothes Show Live, your Model Behaviour, your designated late-night shopping evening at Selfridges. At the flagship Hennes store at Oxford Circus, a full-on, all-comers-welcome, Storm-sponsored scouting afternoon is in full swing. Downstairs, scout Diana and her ex-model protégée Nishan are loitering at the foot of the escalator, studying every newly arrived girl customer. They are clad in Storm-branded T-shirts, which read: 'We Want You', but in fact, they haven't found anything they want so far. 'The problem with girls is, they're generally quite short,' says Diana.
Upstairs, Sarah and Josh are prowling for boys. They are an established team, with an established rhythm. They split up and reconverge every few minutes for whispered consultations, they reassure each other that someone's worth the effort, or worth letting go. If they're not close enough to whisper, they communicate with raised eyebrows and urgent head nodding. They are perpetually giddy on the possibility of the situation.
You watch the teeming teen public, the scouts' resource, and you become stunningly aware of how knowing they are about the whole business of getting spotted. They walk slowly past the scouts, back straight, head up. 'You go into Topshop and you can see them a mile off, just waiting to be spotted,' says Ellis.
At Hennes, there's a gender divide in the way the unscouted attempt to get noticed. The girls loiter near Nishan and Diana, and indulge in strategic hair flicking, but they won't approach. The men are more forthright. 'I want to be one of these Storm models,' a handsome, camp French man tells Josh. 'Am I too old?' He is, it transpires, and too short, but Josh gives him a list of other agencies to contact. The rejected roll their eyes incredulously at the boys Sarah and Josh do scout. 'Boys are like that,' Sarah says. 'If you approach a guy who's with friends, the friends will say: but what about me?'
Spend quality time with the model scouts, spotters like Select's Chrissie Castignetti (the godmother of scouting, who doesn't like to be interviewed or photographed as she thinks her anonymity is a crucial scouting tool), and you'll assimilate scout etiquette. Potentials are not 'pretty' or 'sexy'; they're 'interesting'. That's the language of sexual detachment. Every model is either 'commercial' (read: money spinning) or 'editorial' (read: edgy, directional and credible).
You'll learn that agencies are very possessive about scouting territories. Select's Shaw, for example, is allowed into teen emporium Topshop, but only as a shopper, never as a scout. Models One have an exclusive arrangement with the store, brokered by Ellis, and Select have to respect it.
'I do sometimes stop girls outside,' Shaw admits (the pavement, it seems, belongs to no one). Select is the only agency with a regular presence at annual fashion extravaganza The Clothes Show Live. Storm is going to Glastonbury. Certain London schools are renowned for being particularly fertile hunting grounds, and the agencies divvy them up. Covent Garden and Oxford Street are anyone's. Sarah Doukas does her best work on the streets and beaches near her New Forest home. Ellis owns west London.
There are other rules. Never scout when you're out drinking, says Shaw, because 'You'll get the beer goggles on and pull a minger'. Be very, very sure before you approach someone under any circumstances, says Doukas. 'You've got to be pretty sure that the girl is worth it. I find it excruciating to approach a girl, and bring her in and have the others go, "Hmm, not sure."' If you've turned someone down, never criticise their faces directly, never pull them apart, says Ellis, no matter how much they ask you to explain what's not right with them. And always say, 'You're very attractive, but you're not quite right for us' rather than, 'You're not right.' If girls are with their mothers, approach the mothers first. Look them straight in the eye, talk to them directly and be glad that they're suspicious. They should be. If someone isn't interested, don't push. 'If they haven't got the mentality, it doesn't matter what they look like,' says Doukas. 'This girl I found in Romsey, pushing her kid in a pram, she was exquisite. Her first job was with Juergen Teller and Venetia Scott. Everybody wanted that girl. But she didn't have the mentality. She walked out of the John Galliano couture show in Paris six months after I found her.' She throws up her hands in dismay. 'Caught the train and came home. I could have given her a lobotomy!'
Eastern bloc girls are fabulous looking, but expensive and a pain to organise because of the visas. 'I would also say that sometimes they don't have the personality to make it huge,' says Doukas.
You can't scout in the rain. You can't set yourself targets, you can't say, 'I will find two girls today.' You can't scout for the personality that will transform an OK model into something stellar. That will only become apparent with time.
The scouts happily adhere to the rules because they are high on scout-lust. They all talk about the excitement, the rush, the bonds they form with the girls and boys they find. They all believe they are perpetually a street corner away from finding the next Kate Moss - apart from Doukas, who doesn't think there will ever be a next Kate. Ellis has predictably noble scouting ambitions - crusades, almost. 'I really want to find a fabulous Asian girl. I've been to Southall, I've been to Slough, we've done competitions with Eastern Eye, with The Telegraph, but I just can't find one. But I will. And, most of all, I want to find a really amazing, really beautiful big girl. We need that.' They never switch off. They never leave home without their business cards. They never get bored. And whatever the rest of the world's perspective on their business, however suspicious, critical, morally questionable we, the non-scouts consider them to be, they will persist. 'I wouldn't know how to stop,' says Ellis.