Farm tires filled the doorway, and the two Goodyear managers were trapped in the conference room with angry workers demanding more money in exchange for the inevitable loss of their jobs.
Monday's meeting was not going well.
Goodyear (a global tyre and rubber company) has tried to shutter the plant in the northern city of Amiens for five years without success.
Their latest attempt was met with a "boss-napping," a French tactic that had largely faded away after the height of the economic crisis in 2009.
More theater than actual threat, these aim to grab management's attention - by grabbing management.
The Amiens plant has an especially contentious past. Goodyear's hopes to close the plant have been hindered by violent protests that included bonfires of tires, government concerns and France's prolonged layoff procedures.
Now, the union is willing to accept the inevitable loss of jobs - but at a cost.
"Clearly it was no longer possible to keep fighting for our jobs," Mickael Wamen, the union president, told LCI television.
"So we decided to change tactics and fight for the largest compensation possible."
In exchange for freeing the bosses, they're demanding €80,000 (NZ$131,792) plus €2,500 for each year worked. By late in the day, the managers were still trapped.
Evelyne Becker, a union representative at the factory, said the two were blocked from leaving after an especially difficult meeting with staff.
Goodyear confirmed the two managers were being held against their will.
"This kind of initiative, always to be condemned, is especially inopportune and counterproductive at a time when we should concentrate on the future of employees affected by the restructuring, after several years looking for a solution," Goodyear said in a statement.
The factory and its nearly 1,200 workers have become an emblem of France's labour issues.
Last year, an outspoken American executive who had considered taking it over derided the staff as overpaid loafers.
"The French workforce gets paid high wages but works only three hours. They get one hour for breaks and lunch, talk for three and work for three," Maurice Taylor, the chief executive of Titan tires, wrote to a French government official.
Workers have seized on Goodyear's profitability in their fight against the factory closure, but the company says profit margins have been slipping for years and that the business in Europe isn't sustainable.
The workers have burned tires in protest, fired paintballs at police and come under tear gas spray.
But Monday's boss-napping appeared to take the conflict to a new stage, years after boss-nappings struck at large global companies, targeting foreign managers as well as local executives.
The incidents, which usually last from a few hours to a couple of days, are punishable under French law by five years in prison and a €75,000 fine as long as the boss goes free in under a week.
But generally the workers are not prosecuted, and in many cases they have even tried to make the manager's time in captivity more comfortable.
At a 3M boss-napping in 2009, workers brought the manager a meal of mussels and fries.
Among other companies ensnared in boss-nappings that year: Sony, Caterpillar and a Hewlett-Packard subsidiary.