Mr. Weasley begs Fred and George to not tell Mrs. Weasley they've been gambling. They answer that they have big plans, and Mr. Weasley decides not to ask. The group stays up late talking until Ginny falls asleep at the table. Harry dreams about playing in the World Cup but jerks awake to Mr. Weasley shouting. He can tell that something has changed outside; people are screaming and running. They run out of the tent and Harry sees people fleeing from a group of wizards who are wearing masks and elevating four people high above them. Two of the elevated people seem to be children. As the group approaches, Harry recognizes the man as Mr. Roberts and a wizard flips Mr. Roberts's wife upside down to reveal her underwear.
Fred and George's "big plans" presumably include developing more joke products, which shows that they fully intend to go against their mother's wishes and forge their own way forward in the world. The reader later learns that the masked wizards are Death Eaters, Voldemort's supporters. When they flip Mrs. Roberts upside down, it suggests that there's an undercurrent of sexual violence in Voldemort's overt violence against Muggles and Muggle-born wizards.
Mr. Weasley tells Fred, George, Ron, Harry, Hermione, and Ginny to head for the woods while he, Percy, Bill, and Charlie help the Ministry. After Ron yelps with pain in the dark, Hermione lights her wand. Draco Malfoy shows himself, insults Ron's clumsy feet, and suggests that they move along so that Hermione won't be the masked wizards' next victim. Harry suggests that Malfoy's parents are part of the masked group as Hermione leads Harry and Ron away and into the throng of people. One teen asks Ron where Madame Maxime is in French. Hermione mutters "Beauxbatons," and explains to the boys that it's another magical school.
The undercurrents of sexual violence become important here when Malfoy underhandedly threatens Hermione specifically--she's at risk not just because her parents are Muggles, but because she's female. This shows that Malfoy at least recognizes that Hermione is growing up and will be at risk of prejudice because of her maturing and developing body.
Harry digs in his pocket for his wand but discovers it's gone. He feels very vulnerable without it. Harry, Ron, and Hermione see Winky appear out of bushes, terrified of the "bad wizards" and looking as though she's moving with great difficulty. After she's gone, Harry muses that Winky probably couldn’t move easily because she didn't ask for permission to hide. This sends Hermione into a fit about the unethical working conditions of house-elves. As she and Ron argue, Harry wonders if Malfoy is right and Hermione is in danger. They pass a group of young men trying to impress some veela and finally find themselves alone in the woods.
Because Hermione is a total outsider to Wizarding culture, having been raised by Muggle parents, she looks at the lives of house-elves differently than someone like Ron, who grew up knowing of their existence, does. For Hermione, learning about house-elves opens her eyes to the ways in which Wizarding society isn't fair and just, while in Ron's estimation, Hermione is getting worked up over a normal part of life.
Harry suggests that they can safely stay put just as Ludo Bagman Apparates in front of them. He's shocked to hear that there's a riot going on and Disapparates immediately. Hermione frowns. In the darkness, they hear and sense someone in the bushes. The person shouts "Morsmordre" and a glittering green skull with a snake for a tongue flies into the sky. People start to scream as Hermione, panicked, explains that it's the Dark Mark. Before the three can run, a number of wizards appear around them. They duck in time to miss the wizards' curses and after a few seconds, Mr. Weasley yells for the group to stop.
It's telling that Hermione is the only one of the trio who grasps the gravity of seeing the Dark Mark in the sky. Though it's easy to infer that this is because she's likely read about the Mark and knows what it means (Voldemort, in short), it's also interesting that Ron doesn't seem to get it. This indicates that Wizarding society from Voldemort's downfall to the present has been successfully able to insulate its children from Voldemort's terror.
Mr. Crouch, obviously enraged, asks who conjured the Dark Mark and berates Harry, Ron, and Hermione. He seems to be the only one convinced that any of the teens conjured the Mark and when Hermione points towards where the conjuror stood, several others investigate the dark woods. Mr. Diggory emerges from the trees with Winky unconscious in his arms. Mr. Crouch investigates where she was found while Mr. Diggory tells Mr. Weasley that Winky had a wand and therefore could've created the Mark. Ludo Bagman Apparates to the scene and Mr. Diggory revives Winky.
When Mr. Crouch accuses the trio of conjuring the Dark Mark, it indicates that he's one to act first and think critically about what he's doing later--Harry, as an orphan thanks to Voldemort, is one of the least likely people to conjure the Mark or support Voldemort. When Mr. Diggory suggests that Winky created the Mark, it shows more critical thinking than Mr. Crouch exhibited, given that he's putting together evidence to reach a logical conclusion.
Winky starts sobbing immediately and denies conjuring the Mark. As Mr. Diggory shows her the wand they found in her hand, Harry recognizes it as his. Mr. Diggory accuses Harry of conjuring the Mark but soon walks this back. After a few more minutes of interrogation, Hermione tells Mr. Diggory that the voice she heard was far deeper than Winky's. Mr. Diggory makes Harry's wand show the last spell it performed--revealing the Dark Mark--and again accuses Winky. Mr. Weasley and Mr. Crouch both insist that this is ridiculous and Mr. Crouch takes offense at the implication that he taught Winky to conjure the Mark.
Though the reader doesn't know Mr. Crouch's history with Death Eaters and Dark wizards at this point, his offense at Mr. Diggory's accusation (combined with his uptight appearance and Percy's idolization) implies that he's likely made his name speaking out against Death Eaters. As Hermione defends Winky, she begins to question the authority of the adults around her and trust her own voice and interpretation, suggesting that she's beginning to understand that adults aren't always right.
With Mr. Weasley's gentle questioning, Winky shares that she found the wand in the trees where she was cursed, but she trembles when asked if she saw anyone. She insists she didn't. Mr. Crouch asks to deal with Winky himself rather than turn her over to the Ministry and threatens her with clothes, which will free her. Hermione tries to defend Winky, but Mr. Crouch won't hear it. Mr. Diggory gives Harry his wand and Mr. Weasley herds the trio out of the woods, brushing off Hermione's concern for Winky.
The reader later learns that in this moment, Winky disobeyed Crouch in major ways, but that she did so while trying to fulfill her duties. When Crouch fires her seemingly without listening to her side of the story, it shows that Crouch is willing to put his own power and status above an elf who has served him well for years.
At the edge of the wood, scared wizards ask Mr. Weasley for information. He refuses to give any and when they reach the tent, they discover that Fred, George, and Ginny already made it back. Mr. Weasley explains what just happened and Ron expresses confusion about the significance of the Mark. Mr. Weasley explains that it used to signal death. Bill says that they saved the Roberts family but can't prove who the Death Eaters (Voldemort's supporters) were tonight, while Mr. Weasley tells Harry that they were tormenting Muggles for fun. After a discussion of who might have conjured the Mark, Mr. Weasley sends everyone to bed.
When Ron is confused about the Mark, it reinforces the novel's assertion that the last thirteen years have been extremely safe for Wizarding children, and they haven't lived with the fear that their parents did. For the adults at the Tournament, seeing the Mark likely brought back a sense of terror they haven't felt in over a decade, something that, as Ron grows up, he's going to have to learn to understand and empathize with.