The mystery has been solved. The sigh came from the throat of South Rowan High’s junior quarterback Tim Cook, who had been waiting to exhale for three solid weeks.

Cook was expected by most everyone to be one of the county’s top signal-callers this season. After all, he was pretty decent last year, and he busted his rear end the whole offseason to prepare himself for great things this fall.

South coach Rick Vanhoy can tell you stories about Cook’s “offseason.” Some days Cook would practice basketball or baseball for a couple of hours with the Raider jayvees, then report to the football coaches for a full weightlifting session.

And Cook can tell you stories about his offseason. The hundreds of times he huffed and puffed through steep, downhill sprints to improve his speed.

Cook has the athletic genes (his big brother Daniel was a terrific defensive tackle for the Raiders a few years back). He also looks the part of a quarterback. He’s long and lean at 6-2, 190, with a blonde shock of hair that offers images of a teen-age Boomer Esiason.

But his first two weeks on the job this fall Cook only looked like a quarterback. He didn’t do a whole lot of the things quarterbacks are supposed to do. He was nowhere to be found among the county’s stat leaders. His rushes (mostly sacks) were in the minus column and his passing yardage didn’t make a blip on the radar screen.

In two full games against East Rowan and West Rowan — admittedly two pretty fair football teams — Cook completed all of three passes for 33 yards. That’s about one good minute’s production for North Rowan’s Mario Sturdivant or West’s Jared Barnette.

But all that changed on Friday when Cook cooked with gas in South’s 53-31 loss to arch-rival Kannapolis.

The offensive numbers that South piled up were imposing. The Raiders’ 31 points were the most they’d scored against the men in green since Cook was sitting in a stroller in 1983.

It was the most points that the Raiders had scored since they beat South Stokes 38-7 midway through the 1997 season. In fact, the Raiders hadn’t tallied more than 21 points in any of their previous 17 games.

It was the toss to Kirkman that brought about Cook’s massive sigh of relief, and sent all of those monkeys on his back, scurrying back to the Metrolina Zoo.

“It was just a big relief off my chest,” said Cook, the son of a minister, who punctuates every sentence with “Sir.” “I put the ball in the right place and Jesse ran the right route. It was a great feeling. I felt like I could fly.”

Both Cook and Vanhoy pointed at the improved play of the Raiders’ offensive line as the biggest factor in Cook’s surge from nowhere to a prominent spot on the county leader board.

“Tim can throw the football,” said Vanhoy. “This was simply the first game in which he had time. You let him get his feet set and he’ll do fine. He can throw it, and we’ve got receivers who can catch it.”

“It was the first game I’d really had a chance to make my reads,” agreed Cook, who had to run for his life against both East and West. “I’ve got to give our offensive line the credit for the success I had.”

South is off to an 0-3 start, but there’s a different feeling this year from people who have played the Raiders. No one’s rolling their eyes about the red and black. Everyone acknowledges that South has plenty of dangerous athletes, and that this year, unlike last, they can put points on the board in a hurry.

Most of all, everyone agrees that South has a potentially lethal quarterback in Cook.

“The Kannapolis game was the best game Tim’s had here,” said Vanhoy. “We know what he can do. Now, he’s got to take that success and keep building on it.”

That latest sigh of relief you just heard came from Vanhoy.