I'll try to make a habit of writing these... No promises.
As I've written in the previous chapter, this is a lead up to the 13 Vendémiaire royalist coup attempt. Since I don't want to spoil too much, I'll keep shut about the coup itself.
This manga hasn't touched much on Vendée, but the events here are somewhat connected. Since the beginning of the Revolution, there has been a strong Catholic resistance to the new government. This was mostly due to anti-clerical and atheist views of the revolutionaries, which alienated the conservative peasantry, clergy and parts of nobility.
By the time of this chapter, the Vendée uprising was mostly quashed, but the British were still supporting royalist forces in France by sending detachments of émigrés to the Continent.
A desant of British and émigré troops off the coast of Vendée caused an uprising in a part of Paris early in Vendémiaire (25 September). The Convention only acted on the 4 October (12 Vendémiaire) but the cautious attempts at subduing the royalists failed, and the uprising spread to other parts of Paris. It was only then, that the Convention turned to Barras for leadership. This is where the chapter ends.
The other story of this chapter is fluff about Marquis de Sade. This subplot is actually mostly inaccurate to reality, as de Sade's (in)famous novels did not come out in 1795. The only work of note from that year was Philosophy in the Bedroom, which argued that the Revolution can only survive, if it embraces tha libertine and atheist worldview that de Sade promoted. He was also not released from prison until October of that year, so it's impossible for his work to cause of the uprising.
EDIT: Moreover, Juliette was published in 1799, four years from the time of the uprising, and Saint-Just has been dead since the Thermidor (back in 1794). I don't know why the author is showing him alive.