As the last of the January- and July-born mob members wandered into the early-evening sunlight, two of the restaurant’s employees clutched their heads and paced in frustration. Au Bon Pain policy stipulates no filming for public broadcast—a consideration blatantly transgressed by the long news lenses that caught the scene a moment before.

Outside, the aspiring mob members read and commit their instructions to memory. They are to head toward the greeting-card section of the Coop along a route of their choosing. Whatever their path, however, they must arrive at exactly 7:13 p.m.

Some dawdle in the Square, stopping to listen to the rhythmic clatter of the Funk and Junk players in the Pit. Others pause to chat with friends or to browse the Coop’s bookshelves. The influx of mob makers blends seemlessly with the traffic of tourists and eccentrics that fills the Square each day.

The Coop keeps its greeting cards in three brief aisles on the second floor of its Palmer Street annex. Until ten minutes after seven, the area is virtually empty. A few customers finger through the rows of greeting cards and wander among the software racks.

Then suddenly, a line of people enters through the fire stairway. A line of customers ascending the escalator spills out among the card racks. Within a minute, half of the third floor is filled with the mob makers, who pack themselves shoulder to shoulder in every space available.

Cameras flash. The band of customers smiles. Each participant is to explain, to any confused bystander, that he or she is looking for a card for a friend named Bill. Bill is in New York.

“This last sentence should be spoken as if this explains everything,” the instructions read.

Most of the congregated customers—most of whom represented a relatively young demographic—took their roles very seriously.

Asked whether she had ever participated in a similar stunt before, Alexis Z. Tumolo ’06 shrugged. “Yeah, I buy cards for Bill sometimes,” she said.

The mob was stirring.

“Did you get a card for Bill?” someone shouted.

“They’re out of cards?” another customer cried.

“That’s what I heard.”

Then, at 7:14 p.m., a group of people made hushing noises and suddenly the retail space was eerily quiet.

One mob maker’s cell phone rang. Another phone sounded off. Its owner answered.