The year was 1972 and under the cover of darkness, three men descended into the Montreal Museum of Fine Arts through a skylight, tied up several guards, and made off with $2 million in stolen art, precious jewels and artifacts.
Among the loot, a canvas attributed to Dutch master Rembrandt van Rijn valued at a cool $1 million.
The heist, regarded as one of the largest in Canadian history, remains unsolved; any and all leads on suspects or the fate missing art evaporated decades ago.
How did they do it?
It was past midnight on the night of Sept. 3rd, when the thieves, clad in ski masks and hoods, crept on to the roof of the museum.
"It was a very cinematic theft," said Catherine Schofield Sezgin, a Montreal-born writer and contributor to the Association for Research into Crimes against Art.
In 2009, while taking an association course in Italy, Schofield Sezgin decided to research the skylight caper.
She returned to Montreal for the first time in years to dig through stacks of paper archives and conduct interviews.
Her blog faithfully chronicles the heist and its aftermath.
The thieves were careful in their execution, striking at a moment when the roof skylight was being repaired and the alarm covered by a plastic sheet.
Police believed the robbers accessed the roof by climbing an adjacent tree or propped a ladder up against the building.
Once inside the museum, the three men jumped a first guard as he was making his rounds, then two more, all of whom were bound and gagged. They threatened the guards with guns, firing two warning shots from a 12-gauge shotgun into the ceiling.
Then they set about their work. "They were discriminating thieves and had a fairly good idea of what they were looking for," the museum's spokesperson, Bill Bantey, told CBC at the time.
Along with the Rembrandt, the thieves made off with works by Jean-Baptiste Corot, Gustave Courbet and Pierre-Paul Rubens.
The Rembrandt, Landscape with Cottages, was originally purchased by Canadian railroad baron William Van Horne. It was given to the museum by his daughter years later.
Also stolen was a 18th century French gold watch that once belonged to the wife of Jacques Viger, Montreal's first elected mayor.
The whole robbery took about 30 minutes.
All was going according to plan for thieves — until an alarm was triggered at the service door they planned to use for their escape.
Instead, according to Schofield Sezgin, they had to hurry off on foot with 18 canvases and 39 other items in tow, leaving behind a stack of 20 paintings they couldn't carry.
When interviewed by police, the guards were not able to give descriptions of the thieves, except for noting they had long hair and that two spoke French and the other, English.
Schofield Sezgin spoke at length with Bantey about the skylight caper before his death in 2010. "Everyone forgot about the theft except for the insurance companies," he told her. "Like a death in the family, you have to let it drop."
What happened to the art?
Despite calling in the international police agency Interpol to help track down the thieves, the stolen art was never recovered and the insurance companies were forced to pay the museum's claim.
No suspects were ever arrested and the trail of the missing art has long since gone cold.
That's one thing that Schofield Sezgin still can't quite reconcile: "What's really fantastic is that three people conducted this theft and got away with it, and nobody after all this time has gotten the bragging rights."
Two days after the robbery, the Montreal Gazette reported that it was, in fact, the second lucrative art heist to take place that week, with $50,000 in paintings having been stolen earlier from the Oka home of Agnes Meldrum.
Police said the two incidents bared similarities: both involved three hooded, armed men, two of whom spoke French and the other, English. In the Meldrum case, thieves scaled a 600-foot cliff from a waiting motorboat on the Lake of Two Mountains to access the home.
Following the museum break-in, officials circulated information about the stolen paintings far and wide, hoping to notify international sellers and buyers about their provenance.
It's estimated that most of the pieces have dramatically increased in value since 1972, especially the Rembrandt, which some art experts believe could be worth 20 times more than it was when it was stolen.
And while a haul like that may seem like a golden parachute for the thieves, some experts warn that selling this kind of high-profile material on the black market isn't so easy.
High-profile stolen works often need to lay low for years before they can be transported and sold, said Alain Lacoursière, a former art investigator for Montreal and Quebec provincial police.
Lacoursière, known as the "Colombo of art," made the skylight caper something of a pet project during the 1990s. He was never able to crack the case, but entertains some theories about what happened.
"There were rumours at the time that members of the Mafia here were trying to construct a ship and that the canvases would be rolled up and put in the hold during construction," Lacoursière told Radio-Canada.
"They are probably decorating the home or palace of a Russian, Italian or French Mafia member who may have exchanged them for drugs, weapons."
Not all attempts pay off
This wasn't the first or last attempt made on the Montreal museum's collection.
Schofield Sezgin's research turned up reports of two other attempted robberies years earlier.
In 1933, a thief passed a dozen paintings through an open bathroom window, eventually holding them for ransom. In 1960, thieves were foiled while trying to rob a Vincent van Gogh exhibition.
More recently, two valuable antiquities were stolen from the permanent collection in broad daylight. The 2011 robbery took place during visiting hours on the anniversary of the 1972 crime.
One of the pieces, a fragment of a Persian bas-relief dating from the 5th century BC, was recovered by the Sûreté du Québec in Edmonton three years later.
The second piece, a Roman marble statuette dating from the 1st century AD, was never recovered.