Aidan O'Brien and Camelot ready for their race into the history books by completing Triple Crown with St Leger Even hunched in front of the television in his office, watching a race from Doncaster, the sport seems to occupy his whole being. Camelot was the Arthurian paradise of "glittering romance and optimism" and it works as a description of Ballydoyle. The horse's owners held the name back for 10 years hoping to find an animal worthy of the honour. Today's Doncaster favourite held his side of the bargain, winning the 2,000 Guineas over a mile and the Derby and Irish Derby over a mile and half before confronting the extra 572-yards of Doncaster's autumn stamina test. It may not sound much further, but those extra 2½ furlongs can be a ride into the wilderness. Which is why so few owners and trainer accept the challenge. Since Nijinsky in 1970, only two colts have won the 2,000 Guineas and Derby: Nashwan and Sea The Stars. Both steered clear of the Leger. Before Nijinsky, Bahram, in 1935, was the last horse to display the necessary versatility. More than this: should Camelot's talent stretch the extra yards then O'Brien will become the first trainer to win all five English Classics in a single campaign. On Town Moor, Doncaster's other name, he gives the leg up again to his 19-year-old son Joseph. Already the first father-son trainer-jockey combination to win the Derby, the O'Brien family now seek to annex the Classic calendar along with Anne-Marie, Joseph's mother and Aidan's wife, who helps run Ballydoyle. So there is one big mission left in this sporting summer: a year in which Camelot, despite the boldness of his programme, has taken second billing to Frankel, the Newmarket-trained wonder horse, who has won all 13 of his races from a mile to a mile and a quarter, and who signs off his miraculous career on Champions Day at Ascot next month. Racecourse conjecture suggests there may just be a hint of envy in the Coolmore outfit as the praise stacks up for Frankel. But O'Brien, who dislikes being interviewed, is having none of it. Coolmore, the stud operation that works alongside Ballydoyle, houses the stallion that sired Frankel, who is owned by the Saudi Prince Khalid Abdullah, whose Juddmonte team is one of the few serious rivals to the Magniers, JP McManus and Michael Tabor, Ballydoyle's high rollers. Listen, I can't tell you how much pleasure we get out of watching Frankel, because Frankel is by Galileo and we're lucky enough that we have Galileo. He [Frankel] is trained by a great man, owned by a great man and ridden by a great man. We would have nothing but the height of praise and delight every time he produces. For us it's great that Frankel's there because it just takes a little bit of heat off Camelot. Which is very important for everyone involved. We're just sneaking along there in Frankel's shadow. O'Brien is drawn to shadow. His instinctive gift forces him towards limelight but he is a deeply private man who wastes no words. In an office with few vacant spaces on the wall for pictures of great horses he does not welcome my invitations to describe how it feels to be under so much pressure with so many millions of pounds worth of bloodstock. When I ask whether having your son on board the hot St Leger favourite adds to the trepidation, he says: "I don't know what that means." Inscrutability serves him well. But in open country, by the sweeping gallops and stable yards, he relaxes, talking of the "circle of life" for horses. "If we could never leave this place and hold all the races here it would be great," he says, as Arcadia stretches out ahead of us. His brain is never switched off to the needs of his horses. He talks of their "mental health" and their need to be "happy and relaxed in everything they do." The calypso rhythm of his ring-tone is rarely silent. Dedication has always been his calling card. A champion amateur rider in Ireland in 1994, he became the country's youngest champion trainer two years later, adding the British title in 2001. On his resumé of greats are High Chaparral, St Nicholas Abbey, Galileo, Rock Of Gibraltar, Giant's Causeway, Dylan Thomas and Yeats. This season he has won all four English Classics with Camelot, Homecoming Queen (1,000 Guineas) and Was (Oaks). But now for the coup de grace: the St Leger, part of the Qipco British Champions Series, in which Camelot's opponents include the Derby runner-up Main Sequence and Thought Worthy and Michelangelo from the John Gosden yard. For us all, the dream was some day to have a horse who would be able to compete in the Triple Crown. "You could see when you came in the gate the first thing you meet in Ballydoyle is Nijinsky [in statue form]," O'Brien says. I suppose that for anyone who ever bred a horse, owned a horse, rode a horse, trained a horse [his voice trails off] ... Do you understand? It's probably the ultimate test of a thoroughbred in their Classic year, you know? He also knows: "Extreme distance can break hearts." Accused in the past of building horses" reputations quickly and then rushing them off to stud, the Ballydoyle/Coolmore team are now displaying their willingness to confront more searching tests and sift the breed more rigorously. Dr O'Brien is a very famous man and it's a very famous place. "He set it up and every year that goes by it matures and matures," O'Brien says. John and Sue own it and they're always trying to improve the facility, improve the breed, improve the horse. It's all part of the history of this part of the world, and I suppose more so than ever. "The thing always used to be - "Get him to win races, and then off to stud." As the time went on they felt the quality of the horses they're retiring has to be more and more and more, so they expose the horses more. Obviously they're not prepared to stand horses [at stud] on any kind of a false reputation - that they're the real thing rather than any bits of fake. Really in the last four or five years it's been gradually changing. We get to race the horses more, but it's dangerous for the people who are investing the money in the bloodstock because they are always liable to disappoint and not be worth as much as they would have been when they go to stud. Of Camelot himself, he says: "We've had great horses all through the years and you always hope something different will come along again and then when he arrived it was just incredible. He's an incredible talent, really. One of those very special horses, one that only comes once in a lifetime. The downside is that you're going to totally expose him and he could get beat. Any horse that wins the Guineas, you're always hoping they get a mile and a quarter, and if they get a mile and a quarter you'd say, listen, if you're very lucky they might get a mile and a half, but now we're going to ask him to take the next step. This private world of obsessions looks, to the outsider, hard to inhabit, even with all the beauty. But Camelot can repay O'Brien's faith and care.