It was just the usual teacher-in-service day at Cub Run Elementary School in Centreville Monday, until the limousines pulled up.

Three sleek, shiny long jobs -- a white super-stretch model 30 feet long and two shorter, black standard models -- parked in front of the principal's office about 11:15 a.m. It looked as though someone might have a date with destiny.

Actually, 73 people did. Every teacher and administrator at the five-year-old school was being chauffeured to an elegant lunch at a prestigious restaurant. It was the PTA's way of saying thanks.

"We wanted to really do something for the teachers to show that we appreciate them," said PTA president Stephanie Long, who, along with other board members, solicited area businesses to drum up the free limo service, a luncheon at little cost and gifts for everyone.

For the teachers, the whole affair was a surprise. PTA members kept the secret by sending them invitations last week with instructions to meet in the school's library at 11:30 a.m. Monday and to dress for a nice lunch. Although Monday was a student holiday, the county's teachers had an in-service day.

When Monday rolled around, teachers were still unsure what was in store for them.

"We really have no idea. The PTA is always surprising us. Last year, they held an auction for us," said teacher Cheryl Culler, who noted that the school's PTA is known for going out of its way to support the teachers.

So when the limousines pulled up in front of the school, there was a chorus of oohhs and aahhs. "I've never ridden in a limo," exclaimed third-grade teacher Barbara Smith.

Smith, along with a group of other third-grade teachers, piled into the white lead car, which contained among its assorted gadgets two televisions, a videocassette recorder, a compact disc player and a cellular telephone. No one touched anything. "We were told to be on our best behavior," Smith quipped.

From the sidewalk, shutters clicked as paparazzi from several local newspapers and a PTA member snapped photos, as if royalty had come to visit.

Soon, the three cars pulled out of the school's driveway and were on their way, destination unknown.

Riding in the second limo, two members of a band of mostly second-grade teachers, who proclaimed themselves "the wild group at the school," had the sun roof open and were standing up, checking out the view.

Asked later why she felt she needed to do that, windblown second-grade teacher Donna Buchholz said, "I was just fixing my hair."

Asked if anyone had nipped some of the complimentary brandy from the limo's crystal decanters, there was a definitive "no comment" from Principal Janet LeBel. Back in the first limo, still unsure of where they were headed, the third-grade teachers placed wagers. "I bet we're going to McDonald's," said Smith. "They must have spent all the money on the limos."

"That must be right," agreed "I bet we're going to McDonald's. They must have spent all the money on the limos."

-- teacher Barbara Smith

Peggy Sander. "We'll go through the drive-through."

But five minutes later, with not a fast-food joint in sight, the mini-caravan pulled up to a column-clad mansion, otherwise known as the Westfields International Conference Center, part of a soon-to-be developed 1,100-acre corporate office park. After two return trips to pick up more teachers, the luncheon began.

The meal was served in the center's Washingtonian Room, with green, satiny wallpaper, white tablecloths, china and a large sparkling crystal chandelier overhead, quite different from the head-'em-up and move-'em-out meals in the student cafeteria.

"People really take for granted that they can go out to lunch, but we can't," said Linda Brinkworth. "We usually have to eat in 20 minutes and catch up on everything then."

"There's not even time to go to the bathroom," added Smith, munching on salad. "So this is great."

During the three-course meal of salad, grilled chicken breast or swordfish and chocolate cake, each teacher received a coffee cup filled with bubble gum-flavored jelly beans. Later, a health club membership and two sets of tickets to a Washington Bullets game were given away.

"I'm going to have to give all my students O's {the equivalent of an A} after all this," joked Smith.