London, England (CNN) -- At odds of 33-1, Dream Alliance is not expected to be among the frontrunners at this weekend's Grand National at Aintree -- the UK's biggest and most prestigious horse race.
But the fact the horse will be jumping the famous fences of the Liverpool course at all is remarkable enough -- with Hollywood producers looking for the next "Seabiscuit" already tipping him to make the leap onto cinema screens.
The nine-year-old was raised on a muddy allotment behind a row of houses in the small Welsh town of Cefn Fforest by a supermarket worker and former breeder of whippets and pigeons.
Jan Vokes, who along with husband Brian leads the 22-member syndicate which now owns Dream Alliance, said she decided to go into racehorse breeding after hearing local men discussing the sport when she worked behind the bar of a local social club.
"I liked the sound of it because we'd raced pigeons and we'd had whippets so I thought I'd have a go," Vokes told CNN.
"We bred him with the intention really of just getting a horse on a course and having some fun racing locally. But he just went from strength to strength."
While other race horses benefit from impeccable facilities at stables owned by some of the sport's wealthiest patrons, Dream Alliance's owners have each been paying £10 ($15) a week towards the horse's upkeep for nearly a decade.
Seventeen of the syndicate are locals, many of whom became involved after answering an advert Vokes pinned to the noticeboard of the club where she worked.
Vokes now works in Asda, a British supermarket owned by the American Wal-Mart chain, and admits that her earnings from horse racing haven't enabled her to give up the day job just yet.
But Dream Alliance's story doesn't end there. In 2008 its racing days seemed to be over when it severed a tendon during a pre-National race at Aintree.
Vokes and the syndicate were told there was a 90 percent chance the horse would never race again. But they agreed to use some of his winnings to pay for pioneering stem cell surgery costing £20,000 ($31,000).
Eighteen months later Dream Alliance returned to the course to score the biggest win of his career at last year's Welsh National at Chepstow. That brought him to the attention of U.S.-based Welsh-born filmmaker Justin Golding who signed a deal with owners to tell the horse's story.
Vokes said Dream Alliance the movie will go ahead regardless of the horse's performance at Aintree. She said the build-up to the race had been "unbelievable" -- and admitted to dreaming of yet another improbable twist in Dream Alliance's tale in Saturday's race.
"If we're realistic we're hoping he completes the course and that him and the jockey come home safe," she said.
"But in the back of our minds we don't want to be realistic. We want to dream that he can come home first. When you think about it there are 40 horses that have come to win and anything can happen."