The calm of summer was shattered Monday with the reopening of Quebec universities, where some classes were disrupted as protesters disobeyed the back-to-school law.
The chaotic scenes came in the final stretch of an election campaign where the student unrest has mostly faded into a non-issue.
The reopening of two Montreal universities produced numerous tense moments. Several classes were cancelled by masked, noise-making crowds that banged on pots, pulled fire alarms or blew on air horns while ordering students to leave.
The crowds worked their way from one room to another, determined to clear out classes in any faculty that had voted to continue striking.
That led to confrontations with security, staff and students who wanted to study.
In one case, a teacher blocked protesters from entering a class at the University of Quebec at Montreal. Other teachers simply cancelled classes amid the cacophony. In one case, a class was suspended when no students showed up.
It appeared that no attempt was made to apply the province's emergency law, known as Bill 78, which sets stiff fines for people who prevent students from attending class. Seven protesters were detained at the University of Montreal, but released without charge.
With the provincial election approaching on Sept. 4, the student unrest had hardly been an issue throughout most of the campaign.
The vast majority of Quebec's students have already voted to end their strikes and, at junior colleges, the return to class had been peaceful in recent weeks. But Monday's scenes, as universities reopened, provided a flashback to events that captured international attention last spring.
During the showdown at the University of Montreal, lines of guards stood shoulder to shoulder to block a hallway. They kept a couple of dozen protesters, most wearing masks, from getting close to the classroom where detained demonstrators were being held.
The guards faced a barrage of shouts, and a couple of plastic garbage cans were tossed in their direction.
At one point, the protesters held a vote about whether to charge the line of guards. The group decided against rushing the line after not enough people in the huddle raised their hands in agreement.
Moments later, word spread that riot police had entered the building.
The protesters scattered, knocking over garbage cans and chairs in their wake.
A fire alarm was also pulled, its sound wailing even into classrooms in departments not involved in the conflict.
It was a similar scene across town at the University of Quebec at Montreal, where masked demonstrators entered and disrupted classes.
Protesters blocked cameras and one person taunted a reporter: "It's voyeurism," the demonstrator muttered when a journalist tried gathering images.