Back at the pub, later in the night, two of the Englishmen talk of the need for the Pimpernel to return to France immediately to save the Comtesse's husband, the Comte de Tournay, who has been sentenced to death. But as they begin to read the Pimpernel's instructions for moving forward, they are ambushed by Chauvelin's men. Chauvelin scours the room for evidence and finds a letter signed by Lady Blakeney's brother, Armand. He leaves satisfied, knowing he now has a way to blackmail Lady Blakeney into helping him find the Scarlet Pimpernel.
At Covent Garden Theater, the Comtesse de Tournay attends the opera, only to be reminded of the continuing horrors in France and the unlikelihood that her husband will make it out alive. She remarks bitterly that should Chauvelin need an accomplice, he should seek out Lady Blakeney.
Chauvelin corners Lady Blakeney at the opera and reveals the letter he has found. If she does not help him, he will ensure that her brother is executed. He tells her that if she helps him at Lord Grenville's Ball to discover the identity of the Pimpernel, who is supposed to be meeting with his men in secret during the course of the party, then he will give her her brother's letter the next day, and she can destroy it.
At the ball, Lady Blakeney is paralyzed with anxiety, fearing for her brother's life. She can't explain the situation to her husband, Percy, who she finds completely useless, and thus believes she must shoulder the situation alone. She follows two of the Englishmen and sees them hand-off a note. She follows the man who has the note to a room, where she distracts him long enough to read it just before he sets it to flame. The note says that the Scarlet Pimpernel will be in the supper room at one o'clock.
Lady Blakeney tells Chauvelin what she has read in the note. He goes to the supper room, only to find Percy Blakeney napping on the sofa in the corner. Chauvelin stretches out on a couch as well, waiting for the Pimpernel to appear. He doesn't, and Chauvelin tells Marguerite that she better hope that the Pimpernel is caught: her brother is not saved yet.
Chauvelin becomes a real villain when he orchestrates an ambush on the league of the Scarlet Pimpernel, but he's a complex villain in that he doesn't seem innately evil or cruel. The adventure genre makes a staple of the abnormally brutal or deviant villain (often with a scar) who butchers victims, increases the body count, and preys on our fears, so that when he finally meets the hero in a climactic encounter, we fear not just the hero's death, but his suffering.
Meanwhile, Chauvelin seems a bit of a mouse. We aren't particularly afraid of him personally -- but what we are afraid of is his power, for he has the office to send any aristocrat to the guillotine of the revolutionary mob. And as the reader, it is the guillotine that we fear, not any individual combat between hero and villain.
Chauvelin presents the initial plot crisis with the revelation that Armand is part of the League of the Scarlet Pimpernel. This single letter provides the impetus for all that is to follow - for now Lady Blakeney has her own sympathies torn, between saving her brother and betraying the Pimpernel. But whereas Percy chooses the Pimpernel over blood, Lady Blakeney chooses blood over allegiance to the hero and tells Chauvelin she'll help him find the stealthy Englishman.
Orczy pulls off the best sequence of the novel in the run-up to the secret meeting between the Pimpernel and his followers at Lord Grenville's ball. For when we arrive at the secret meeting room, through the eyes of Chauvelin, only to find Percy, we as the reader fall for the trap, believing Percy an innocent bystander. Certainly the clues have already been laid for us to feel foolish when it is revealed that Percy is the Pimpernel, but she uses three main devices to distract us -- the omniscient narrator, who we've so far trusted as representing the truth, but who now happily misleads us by using the filters of Chauvelin's point of view; the failure of Lady Blakeney to take her husband seriously; and the consistent build-up of the revelation of the Pimpernel, as if he is to be a new character that can finally take the place of protagonist.
That said, it is clear now that Lady Blakeney is the emotional center of the novel, for more and more Orczy's narrator takes times to examine her torn feelings. If there is a fault to the storytelling in The Scarlet Pimpernel, it is Lady Blakeney's failure as the protagonist to truly drive the action. More and more as the novel progresses, we are privileged to Blakeley's interior thoughts; however, she merely responds to her torn allegiances, wallowing in the difficulty of her position without doing anything about it.