Harry and Hermione race through the panicking crowd, trying to find Ron. They find him and Hermione Apparates with them to Tottenham Court Road in London. They walk and Harry laments not having his Invisibility Cloak. Hermione leads them into an alley and out of her tiny beaded purse pulls out changes of clothes and the Cloak. She explains that she has an Extension Charm on her purse. She shakes it and they hear the books tumbling. Hermione assures Harry that they can't go back; the Death Eaters are after him and the Order will protect wedding guests.
This is the first instance in which Harry truly discovers that he couldn't do this without Hermione—she had the foresight to pack everything they'd need and was able to get them out when Harry was more concentrated on just finding his friends. Should Harry choose to learn from this, it will show him that he needs all the qualities his friends bring to the table in order to be safe and successful.
Hermione leads them into a greasy cafe. They order coffees and Hermione hisses that they already know what Voldemort is up to; there's no need to head for the Leaky Cauldron. A minute later, two workmen squeeze into another booth. They wave their waitress away as Hermione reaches into her purse for money. The workmen draw wands, as does Harry, and they shoot spells at each other. Harry Stuns one and tries to get the other. Hermione binds the man after he blows up part of the cafe. Harry and Ron recognize them as Death Eaters, lock the door, and turn out the lights. Hermione performs a Memory Charm on them while Harry and Ron put the cafe back in order.
The fact that these Death Eaters were able to find Harry, Ron, and Hermione suggests that there's already magic at work that the trio don't know about, given that it's unclear how the Death Eaters discovered where they went. This gives the trio one more thing that they'll need to find out as they go forward, as knowing how to keep Voldemort from finding them will be one of the most important elements of staying safe.
Harry, Ron, and Hermione wonder how the Death Eaters found them. They wonder if Harry still has the Trace and, feeling contaminated, Harry suggests they split up. Ron and Hermione refuse, but Harry is able to convince them to go to Grimmauld Place. They reason that Snape is the only Death Eater who can get in, and they know that Moody put charms in place to thwart Snape's entry. They Apparate there and let themselves in. The entryway is dark and empty, and an overturned umbrella stand is the only thing out of place. Harry takes a step forward. Moody's voice asks, "Severus Snape?" and the trio's tongues roll up and flatten again. Then, a horrific effigy of Dumbledore flies at them and explodes when Harry says that they didn't kill him.
Choosing to return to Grimmauld Place represents a choice by the trio to trust in their wider community to protect them. Especially since Harry is also unsuccessful in getting Hermione and Ron to leave him, this impresses upon Harry the importance of relying on his community, both large and small, to make his way easier. That Moody's charms are still effective after his death shows how a person can continue to create meaningful change even after death; he's directly responsible for keeping Snape out of Grimmauld Place.
Harry leads them down the hallway. Hermione raises her wand and whispers, "Homenum revelio." When nothing happens Ron comforts her, but Hermione snaps that she checked for human presence and nobody's here. They go up to the drawing room and Ron looks out the windows. He suggests that Harry can't have the Trace since there aren't any Death Eaters outside, but Harry can't pay attention—his scar starts burning with pain. Ron asks Harry if he saw anyone at the Burrow, but Harry says that Voldemort is just angry. Hermione shrieks for Harry to close his mind. Harry turns angrily away, but a weasel Patronus flies through the window and, in Mr. Weasley's voice, says that the family is safe and to not reply.
Mr. Weasley's request that Harry, Ron, and Hermione not reply signals that the trio is now effectively cut off from the rest of their community. In this moment, the knowledge that the family is safe might be good, but it doesn't feel as meaningful, given that it's unsafe to attempt to make contact with them later. As they now set off on their own, all three of the trio will begin to come of age and become more independent out of necessity—there are no adults to help them anymore.
The pain in Harry's scar reaches a peak as Hermione asks if they can all sleep in the drawing room. Harry excuses himself to the bathroom, locks himself in, and finds himself in Voldemort's eyes, torturing one of his Death Eaters with Draco Malfoy's help. Harry comes to in the bathroom, haunted by the terrified look on Malfoy's face.
That Draco is so horrified by what he's doing suggests that Malfoy is less interested in helping Voldemort than he is in surviving. This gives him the room to make choices that will allow him to atone for what he's done and emerge a better person when all is said and done.