It has been fun to speculate about the boxy, industrial structure that Turner Construction workers erected over the last few weeks atop a barge moored at the Admiral Harold E. Shear State Pier in New London. People love a mystery, and the secrecy surrounding the strange project created one.

Turner Construction wasn't talking. Logistec USA, which leases the pier from the Connecticut Department of Transportation, said Turner never informed them about the purpose of the building. A DOT official said the department was not involved.

Most fascinating was the ability of such an unimaginative structure to fuel so many imaginings. Four stories high with the dimensions of a narrow shoebox, the structure is largely featureless, all 90-degree angles and only slots and window-like squares to interrupt its monotonous façade. The first floor is a grayish black; the top three stories white.

A movie set, perhaps? Sci-fi cyborgs would certainly be at home in the shoebox. Could it be a secret defense project? (In the middle of a busy waterfront and ferry terminal? Not likely). A prison? Now that would be cruel and unusual.

Early Wednesday afternoon a tugboat began moving the barge, the floating rectangular structure making for an odd manifestation as it moved across New London Harbor toward Long Island Sound. Labor stopped in upper story offices as workers watched. Ferry passengers pointed. Theday.com recorded the dull object and its slow exodus, the video shooting to number one as the most viewed media offering on the website.

In Portland, where the barge arrived Thursday at "Rickers Wharf," at the end of Commercial Street, the speculation resumed. Word had already spread of the strange object's journey from New London.

Portland Press Herald reports began to strip away some of the fancy. Peter Vigue, chairman and CEO for The Cianbro Cos. confirmed his company would be installing interior features and "outfit the building with a substantial amount of technology."

He wouldn't say more.

"I don't have the authority to speak on behalf of my client," he told a Press Herald reporter.

Patrick Arnold, director of operations and business development for the Maine Port Authority, offered the most plausible - and boring - of explanations.

"Looks to me like a modular fabrication for an industrial site," he said.

Cianbro shipped three modules to an iron ore mining operation in Newfoundland last year for use as control centers, the Press Herald noted. Another official familiar with Portland's industrial waterfront operations speculated New London's shoebox could end up as a control center at a $14 billion oil field expansion Exxon is undertaking, also in Newfoundland.

It was more fun when we didn't have a clue.