Paris, early 90s. AIDS has been raging in France for almost ten years, but large parts of society are still silent about the epidemic. Mitterrand's government does not care about sexual education and the pharmaceutical lobby drags out the development of new drugs. Act Up, an activist group of those affected, wants to draw attention to the grievances. When Nathan, who is HIV-negative himself, joins Act Up, he falls in love with Sean, the bravest and most radical of the group. Together they fight on the front line.