CHICAGO — Be careful when betting against Magna Fortuna.

The 3-year-old dark bay gelding, known to his friends simply as Taxi, will run his second race ever when Hawthorne Race Course begins its spring meeting this month.

To get this far, he has been the longest of long shots.

How long? Well, by all rights, he should be dead.

"Considering how the stars had to align to get him here, he’s an incredible long shot," said Gail Vacca. "Pretty much off the charts."

Taxi’s story begins with Vacca, founder and president of Illinois Equine Humane Center, a horse rescue, advocacy and education organization based in Big Rock, about 45 miles west of Chicago. She sometimes attends what she calls "kill auctions," where unwanted horses are sold for as little as $25 and shipped to slaughter.

"It’s pretty much egregious cruelty," she said on a recent cold morning at Hawthorne, in Stickney. "The horses here are loved and pampered. They’re treated like kings at the track. Then that world is shattered. They become meat on the hoof. They’re thrown into pens with all these other horses, and they’re not used to that environment. There’s kicking, biting. The horses are terrified."

At such an auction in June 2009 in Shipshewana, Ind., Vacca saw a lame mare struggling to stay on her feet in the overcrowded kill pen. She’d been sold to a dealer who intended to haul her to Canada to be slaughtered.

Vacca, a former thoroughbred trainer who has been involved with horses for more than 40 years, recognized the mare as a thoroughbred. She spent the day haggling with the dealer, who finally agreed to sell the horse for $300.

"She could hardly stand; she had trouble with her front legs," Vacca said. "I knew that if he put her in that trailer with the other horses, she’d fall down and would be trampled to death before they ever got her to Canada."

She took the mare home, knowing she might have to euthanize her — preferable to death in a horse trailer or slaughter plant, Vacca said. But first, she wanted to give the mare one more chance. And with corrective shoes and treatment, the horse began to recover.

Soon, Vacca noticed that the mare — now dubbed Lulu — was showing signs of being in foal. A vet confirmed it, and Taxi came into the world on April 15, 2010.

One look at the foal and it was evident Lulu had been keeping good company.

"Before, I didn’t know what he was, a Heinz 57 or what. When he came out, it was just obvious," Vacca said. "People who know dogs know the difference between a poodle and a German shepherd. It’s the same with people who know horses. It was pretty clear he was exceptional. Good conformation, good presence."

Then Vacca went on a quest, first to learn who Lulu was, then how she ended up in a kill pen, and finally who Taxi’s sire was. A series of Internet searches, emails and phone calls brought some fascinating answers.

Lulu was really Silver Option, who had become a broodmare after a brief and winless racing career. When her owner thought she had lost a foal conceived earlier in 2009, he sent her to the "kill auction."

And Taxi’s sire was Magna Graduate, a $2.58 million career stakes winner who was standing stud at the prestigious Darby Dan Farm in Lexington, Ky.

Taxi was from Magna Graduate’s first crop of foals, so he had no track record as a sire. But clearly, the pedigree was there, along with the classic long legs and neck. (Lulu, incidentally, has largely recovered from her leg problems and now lives in happy retirement at the rescue.)

Having a racehorse isn’t the same as running one, of course. It takes between $25,000 and $30,000 a year to maintain a thoroughbred, money the small rescue organization didn’t have. So Vacca and others from Illinois Equine Humane Center decided to form a partnership, Rescue Me Racing. Sixteen shares were created; an initial payment of $1,000 to get into the group was in the form of a donation to the equine humane center, and the partners now share costs. Suddenly, Taxi, registered as Magna Fortuna (Latin for "good luck" or "good fortune"), had a huge adoptive family.

"It’s fun," said retired pilot Charlie Deveaux, of Bartlett, Ill., who went into the partnership with a friend, Clay Kannaka, of St. Charles. "My buddy was always very interested in owning a horse. When I started volunteering (at the equine humane center) a year ago, Gail introduced me to the partnership."

To train Magna Fortuna, the group brought in Michele Boyce, a licensed trainer for 25 years. The horse has impressed her.

"I didn’t see him before he came in (to Hawthorne), but I’d get pictures weekly," she said. "We have a lot of good photographers in the group. He was a sturdy, sound colt. From the first time I saw him, he always looked good."

In Magna Fortuna’s one start, in a 6-furlong race in December at Hawthorne, he was given the challenging outside No. 11 slot in a field of 12 horses, most of them more experienced. He finished ninth.

"He’s showed a lot of promise in training," Boyce said. "His first race wasn’t the best, but he learned a lot. He’s gaining maturity, which I like to see. But he’s like a kid; he’s still learning."

Boyce said she has noticed more concentration. "He’s always trained well, but he’s less of a goof-off. It might take a couple of races to focus, but I’ve liked everything I’ve seen about him."

The date for Taxi’s first race of the spring meeting, which runs until April 28, isn’t set yet. The partnership, which will funnel a portion of any winnings to the Illinois Equine Humane Center, has agreed he won’t be entered in claiming races, where horses can be claimed by other owners for a set price. And there won’t be any big paydays from stud fees at the end of the road because Taxi has been gelded. The next chapter of Taxi’s story waits to be written.

"If he’s not competitive at the allowance level and we’re spinning our wheels, we’ll retrain him as a jumper or for dressage or as a trail horse, whatever suits him best," Vacca said. "Some owners may not want to continue, but I suspect the only problem we’ll ever have is a 16-way custody battle for him when he ends his racing career."