Summary
Lady Blakeney and Percy go to their country home outside the city of London. Under the stress of all of her dealings with Chauvelin and the coolness of her husband, Lady Blakeney explains the circumstances that led her to denounce the Marquis de Cyr's family at the tribunal -- namely that she was tricked into the condemnation.
Percy isn't sympathetic. He tells her that she should have revealed her role earlier. Lady Blakeney asks for her husband's help in saving her brother but Percy remains cold. He says that perhaps she should ask Armand, but Lady Blakeney isn't sure how to tell him that she needs her husband's help, since it's Chauvelin who is blackmailing her.
Still, Percy perceives his wife's fear and assures her that her brother will be safe -- though he still withholds even the slightest sign of affection. Lady Blakeney fears that she has lost her husband's love for good. Only when Lady Blakeney leaves, despondent by her husband's refusal to show her love, do we see Percy break down, clearly still very much in love with his wife.
Lady Blakeney realizes she has always been in love with Percy and that she has underestimated him. The next day she finds Percy about to leave for the North, and is surprised by his mysterious departure. And yet she feels confident that it has something to do with his promise to save her brother.
Lady Blakeney takes the opportunity of Percy's absence to peak into his study, which is organized and neat. She wonders why Percy presents the image of the buffoon, when he is clearly a competent and thoughtful man. She sees a small gold ring on the carpet, which she picks up. It has a flat shield, engraved with a scarlet pimpernel. Lady Blakeney suddenly realizes the true identity of her husband.
Indeed, not only does she realize her husband's true identity, but Lady Blakeney also realizes that she has unwittingly betrayed him to Chauvelin, who plans on intercepting the Pimpernel in Calais. Soon a messenger arrives carrying her brother's letter -- which Lady Blakeney takes as evidence that Chauvelin is close to catching the Scarlet Pimpernel.
Analysis
This stretch of chapters is primarily about the relationship between Lady Blakeney and Percy, which deepens the complexity of our two central characters just before the key revelation of Percy's secret identity. It's curious, of course, that The Scarlet Pimpernel is nearly half over before we know our hero, for we never really see the enigmatic rescuer in action until after Percy is revealed to be the Pimpernel. In this light, the book seems to be a romance masquerading as an adventure, more a story of a broken marriage mended by the revelation of heroism in both husband and wife.
When Lady Blakeney tries to confess to Percy the circumstances of her denunciation of the St. Cyr family to the tribunal, Percy is uncharacteristically cold. For the first time his mask of buffoonery drops, and we see him as a man capable of feeling and depth. Indeed, when he tells his wife that he will ensure Armand's safety, we not only believe him, but begin to suspect that he has a dual nature -- one that justifies his level of intensity.
That said, Percy still does not take over the role of hero here. We remain in Lady Blakeney's point of view, confused as to his sudden disappearance, confused as to his identity until she finds the ring in his study. Percy is less an adventure hero and more a romantic one; we see him through the eyes of his beloved, and regaining love appears to be the primary goal of the story, rather than the rescue of parties in danger. Before the "adventure" story can properly begin, we first address the "tragic romance" story. With Percy's worthiness and identity established, Orczy finally sets about giving her audience the adventure they've been expecting.
Structurally, it is important that we note the use of "hooks" at the end of each chapter, especially as we delve into the action-adventure portion of the novel. The Scarlet Pimpernel is not so unlike a TV serial or a serialized novel in that it depends on the suspense of the final sentence or paragraph in order to raise the reader's adrenaline and expectations in advance of the next section. For instance, later in the book, we'll hear Percy sing "God save the King!" to announce his arrival at key moments, an action that makes zero sense since he's attempting to hide from the authorities, but one which builds suspense for the reader. Thus, at the end of this section, when Lady Blakeney finds the Scarlet Pimpernel ring, it is a terribly convenient discovery -- a coincidence that might even lead a reader to groan -- but one that works well as an end-of-chapter hook.