Clock watching ... the Pantheon in Paris. Photograph: Alamy
Just so long as there isn't an albino monk into self-flagellation....
It is one of Paris's most celebrated monuments, a neoclassical masterpiece that has cast its shadow across the city for more than two centuries.
But it is unlikely that the Panthéon, or any other building in France's capital, will have played host to a more bizarre sequence of events than those revealed in a court last week.
Four members of an underground "cultural guerrilla" movement known as the Untergunther, whose purpose is to restore France's cultural heritage, were cleared on Friday of breaking into the 18th-century monument in a plot worthy of Dan Brown or Umberto Eco.
For a year from September 2005, under the nose of the Panthéon's unsuspecting security officials, a group of intrepid "illegal restorers" set up a secret workshop and lounge in a cavity under the building's famous dome. Under the supervision of group member Jean-Baptiste Viot, a professional clockmaker, they pieced apart and repaired the antique clock that had been left to rust in the building since the 1960s. Only when their clandestine revamp of the elaborate timepiece had been completed did they reveal themselves.
"When we had finished the repairs, we had a big debate on whether we should let the Panthéon's officials know or not," said Lazar Klausmann, a spokesperson for the Untergunther. "We decided to tell them in the end so that they would know to wind the clock up so it would still work.
"The Panthéon's administrator thought it was a hoax at first, but when we showed him the clock, and then took him up to our workshop, he had to take a deep breath and sit down."
The Centre of National Monuments, embarrassed by the way the group entered the building so easily, did not take to the news kindly, taking legal action and replacing the administrator.
But the UX, the name of Untergunther's parent organisation, is a finely tuned organisation. It has around 150 members and is divided into separate groups, which specialise in different activities ranging from getting into buildings after dark to setting up cultural events. Untergunther is the restoration cell of the network.