His ominous apparition prepares the audience for the crisis.
"Citizens!" screeched the shrill voice of Robespierre "others have placed before you flattering pictures; I come to announce to you useful truths.
....
"And they attribute to me,--to me alone!--whatever of harsh or evil is committed: it is Robespierre who wishes it; it is Robespierre who ordains it.

Is there a new tax ?--it is Robespierre who ruins you.

They call me tyrant!--and why?
Because I have acquired some influence; but how ?--in speaking truth; and who pretends that truth is to be without force in the mouths of the Representatives of the French people?
Doubtless, truth has its power, its rage, its despotism, its accents, touching, terrible, which resound in the pure heart as in the guilty conscience; and which Falsehood can no more imitate than Salmoneus could forge the thunderbolts of Heaven.

What am I whom they accuse?
A slave of liberty,--a living martyr of the Republic; the victim as the enemy of crime! All ruffianism affronts me, and actions legitimate in others are crimes in me.

It is enough to know me to be calumniated.