The weird-thing mystery began with an e-mail from a Capitol Hill operative.

“This is a weird thing that got put into the sidewalk,” wrote Vince Morris, who was a newspaper reporter before he became a Senate spokesman and has retained his appreciation of the weird.

A photo was attached.

It showed a gleaming stainless-steel pedestal with a mini-Parthenon of the same steel sitting on top of it. It was an inch from a manhole that sat above a sewer set in a street corner in Capitol Hill.

A stainless steel pedestal topped with a mini-Parthenon appeared on the corner of Second and E. Capitol streets. (Ashley Halsey III/THE WASHINGTON POST)

“My question: Who the heck approves putting this kind of thing right in the middle of the sidewalk?” Morris said, predicting, “It’s gonna be a good story.”

John Lisle, a District transportation guy, knows the city’s street corners like peanut butter knows jelly. He pondered the photo for a minute.

“I have no clue,” he said.

Surely, someone did?

A visit to the street corner, Second Street and East Capitol, was in order.

“I’ve never seen anything like it,” said Carol LeNeveu. But perhaps, she said, that was because she was just visiting, from “the other capital, Ottawa, Canada.”

“We have boxes like those,” she said, pointing to a row of newspaper and leaflet boxes about 20 feet away, “but nothing like this.”

A stainless steel pedestal topped with a mini-Parthenon appeared on the corner of Second and E. Capitol streets (Ashley Halsey III/THE WASHINGTON POST)

But her good Canadian instincts provided the first clue: “It’s definitely related to the Supreme Court.” She pointed once more, this time across Second Street to the back side of the Supreme Court building.

The next clue came from Nealy Harnsberger, who was on her way to work in the building that sits on the opposite corner, the Library of Congress.

“It says ‘free,’ so there must have been something inside it, a flier, maybe?” she said, observing that a plastic enclosure about the size of a country mailbox sat between two rows of eight pillars.

There was a hinged door on one end and the word “Free” emblazoned just below it. The box was empty.

A businessman in pinstripes who said he was from Fairfax but declined to reveal his name made the next helpful observation.

“It’s probably something supported by the city because if it was a company they’d have their logos all over it,” he said.

Donald Gilman added to a growing body of knowledge. He was on his way to the building on the third corner of the intersection, the Folger Shakespeare Library, where he’s been doing research on French literature while on sabbatical from the University of Indiana.

“It’s been here for about a month and there were some sort of fliers in it at first, but when it says ‘free’ I generally don’t take it,” he said, pausing to note: “They keep it up nicely. It’s very well polished.”

Matt Holton lives “oh, pretty close” to the corner and confirmed what LeNeveu suspected about the court connection and what Gilman observed about the timing of its arrival. He had reached in to take one of the fliers a few weeks earlier.

“It was a map that had something to do with the Supreme Court,” he said. “If I can find it, I’ll let you know.”

Perhaps, someone suggested, you should ask in Florida House. That would be the building behind the lovely garden that sits on the same corner as the steel Parthenon.

The sign on the door invites visitors to ring the bell. The brief wait was worth it, because the gracious Julianne Mica answered.

She says Florida is the only state that has an embassy in Washington. It was opened in 1973 for “the use of the people of Florida” by a visionary who thought other states would follow suit to create an embassy row of the republic. They didn’t.

Mica has been a Florida House ambassador for three years, and she confirmed Gilman’s recollection of the timing of the arrival of the weird thing.

“We were kind of scared when we first saw it,” she said.

Undeterred, she investigated. Call the D.C. arts commission, she suggested with a knowing smile.

“Oh, yes, yes, yes,” said Marquis Perkins of the D.C. Commission on the Arts and Humanities when the weird thing was described to him.

The arts commission has a history of adding dollops of pizazz to the city. It spread 100 donkey and elephant sculptures around town back in 2002, when people still found partisan politics amusing. Two years later it did the same thing with 150 colorful panda sculptures.

Perkins put Mary Beth Brown, a public art coordinator for the commission, on the phone.

Thereafter, the weird thing became known as “the vending device.”

“The vending device contains prints on how to build your own Supreme Court out of cardboard,” Brown said, revealing a purpose that none of the passersby had come even remotely close to guessing.

Four cardboard models of the building, each about five by seven feet, were built by students of the Corcoran College of Art under the tutelage of well-known design artist Wolfgang Weileder.

They were put on display around town starting on March 20. It didn’t rain a heck of a lot in the next two weeks — a little more than half an inch — but that was enough. Cardboard gets a little droopy when wet.

The fourth one was coated in lacquer and placed outside the D.C. Jewish Community Center on 16th Street NW on April 3.

“It’s looking pretty good, so hopefully the weather holds up,” Brown said.

Brown was dismayed to learn that the weird-thing vending device had been empty for a while.

“Oh no, when did you go?” she asked. “I’m actually going to drive by this afternoon and stick more of the prints in there. I’m sorry you didn’t get one.”