It was 1923 and Ugo Sivocci was unhappy. The legendary Alfa Romeo race-car driver had been coming in second, and he didn't much like being an also-ran.

To change his luck for the upcoming Targa Florio race in Sicily, he painted a white square containing a quadrifoglio, or four-leaf clover, on the front of his Alfa Romeo RL Targa Florio.

He finished first in that race.

Later that year, he was track testing a new car that wasn't yet graced with his lucky four-leaf clover. He crashed and died.

With his death, a tradition was born. Henceforth, Alfa race cars would display the quadrifoglio within a white triangle instead of a square, with the missing fourth corner symbolizing Sivocci's passing. After World War II, the quadrifoglio was also employed to designate high-performance street vehicles like the 1963 Giulia TI Super and the 1965 Giulia GTA.

And now it is decorating the front fenders of what has to be one of the most exciting sport sedans I'll ever drive: the all-new 2017 Alfa Romeo Giulia Quadrifoglio (pronounced Julia Quadrifolio).

This new, rear-drive Alfa, which will start arriving in showrooms later this month, had strangers interrogating me in shopping center parking lots and in the shadow of gas pumps.

I told them that it is powered by a brand-new aluminum V-6 that, with the help of two brawny turbochargers, derives 505-horsepower and a hefty 443 pounds of torque from a measly 2.9 liters. I would explain that this much power in a relatively light sedan translates into a stunning weight-to-power ratio of 7-1, or seven pounds per horsepower. Your family car is probably more like 20-1.

And yes, it is blindingly fast. This car goes from a standing start to 60 mph in a factory-claimed 3.8 seconds, and then moseys on up to 191 mph. That's supercar turf. And after tickling 200, it shuts down as hurriedly, thanks to big Brembo high-performance brakes that boast six-piston calipers up front and four pistons in the rear.

Unfortunately, I tell a fellow supermarket parking lot denizen, Alfa isn't offering the Quadrifoglio with the manual gearbox in this country. But it is equipped with a trusty, quick-shifting ZF eight-speed automatic that employs close-ratio gears to keep the engine residing in the power band's penthouse.

The Quadrifoglio's engine performance, I tell the middle-aged man refueling his Chevy Silverado, is matched by its handling, which is superb. The cornering facility is due, in part, to some very sophisticated electronics - including the unique, electronically controlled aero front splitter that controls downforce. In the straights, the splitter closes to minimize wind resistance. In the corners or during braking, it furnishes up to 220 pounds of downforce to maximize balance.

The splitter, like the car's roof, hood, steering wheel, driveshaft, and much of its exterior and interior trim, is made of light, strong, and expensive carbon fiber.

The Quadrifoglio also has selectable driving modes that tailor throttle response, turbo boost, suspension damping, and the exhaust note to the driver's desires. Want to rock and roll on the track? Dial up "dynamic" or "race." Want maximum ride comfort? Try "natural."

The Silverado driver was right: The Quadrifoglio's body design is distinctive, and the tester's black, leather-appointed interior was gorgeous.

The Quadrifoglio's estimated $70,000 price tag is more than most of us have to spend on a car, of course. But, when you consider what this automobile will do, how sophisticated and luxurious it is, and its considerable exclusivity, that's not unreasonable money.

The test car is in another gearhead's garden by now. I miss it.