It's Halloween night. Ding-dong.
You open the door and find a tall, gangling creature standing on your stoop.
You can't see its face because it's hidden behind one of those spooky Scream masks. (Though sometimes, the more brazen ones don't bother hiding their faces at all.)
"Trick-or-treat," the creature mumbles. (Though sometimes, the more brazen ones don't say anything at all.)
Reluctantly, you hand over the candy, even though you're thinking this creature is a little old to be panhandling Halloween treats.
But just how old is too old?
"To me, when you hit teens, that's too old," said Jackie Finnell, a cosmetics saleswoman. "I just think it's for the younger children."
The little tricksters are cute, said Finnell, "but when a great big kid comes wrapped in a sheet ... sorry."
In the absence of a legal age limit, families are left to resolve this dilemma on their own.
Some parents cut off their kids at 13. And middle school seems to be about the age when kids themselves begin rethinking this whole business of begging for candy.
"Boys, for example, in eighth and ninth grade, will make a quick run just to get some food, that kind of thing," said Rod Shriwise, an eighth-grade counselor . "They don't get all hyped and dressed up. They'll just throw on a mask. It's not a big priority."
Shriwise doesn't think parents should cut off their kids from trick-or-treating but should set at least one ground rule.
"If they're still going to go out, they should play the game," Shriwise said. "In the spirit of Halloween, you need to dress up. And if you can't do that, you can't go trick-or-treating."
By the time kids have a driver's license, many are off to haunted houses and parties instead. Especially teen guys. All the ones we asked said their friends don't trick-or-treat anymore. One poor man, 30 now, said he swore off when he was 13 after an old man yelled at him and slammed a door in his face.
Some teens, though, have turned trick-or-treating into community service, collecting canned goods for the needy instead of candy.
The Halloween die-hards, most of them girls, are still out workin' the sidewalks. They've learned to mask their age by, well, wearing masks. Some volunteer to walk little brother or sister around the neighborhood so they can snag some loot, too.
Sixteen-year-old Megan Smith still trick-or-treats even though most of her friends stopped years ago.
"I'm going to dress up forever," Megan declared one recent afternoon while shopping at a local mall. "All of my friends are trying to rush and be grown up."
Megan and her best friend, Nicole Reynolds, who are high school juniors, simply ignore all the looks they get from homeowners, those brow-furrowing glares that seem to accuse: "Aren't you too old for this?"
Some people, said Nicole, just come right out and say it.
Jill Conaghan, a 12-year-old seventh-grader, doesn't think kids should be cut off from the fun just because they reach a certain age.
"There's no age when you're too old," Jill said one recent day after school as a group of her friends nodded in agreement. "Why shouldn't you be able to go out and have fun?"
Halloween is a fun holiday and doesn't stop being fun "just because you turn 13," said Melissa Hyder, a doctoral candidate in psychology and an undergraduate psychology adviser at University of Missouri at Kansas City.
If people feel that strongly about not "treating" teens, Hyder said, maybe they should post age-limit signs on their doors.
Hmmmm. Or maybe one of those height-requirement signs used on amusement-park rides: "If you're taller than this line, no candy for you."