Muggles' Guide to Harry Potter/Books/Deathly Hallows/Chapter 21

Synopsis.
Xenophilius Lovegood explains that the Deathly Hallows mark is not Dark at all, though a burly young man at Bill and Fleur's wedding thought it was. It is actually a sign indicating one is on a Quest for the Deathly Hallows, and it is from "The Tale of the Three Brothers". Harry has never heard of it, but Ron and Hermione have; Hermione reads the story aloud from "The Tales of Beedle the Bard". 
Xenophilius, though uneasy, further relates how three brothers cheated Death and received artifacts from him. These were the Elder Wand, a wand that was unbeatable in a duel; a Resurrection Stone, which, when turned three times, summons souls from the afterlife to the living world; and Death's own Cloak of Invisibility. Together, these items form the Deathly Hallows, and despite it being a fairy tale, the Three Hallows actually exist. Recalling the symbol on Ignotus Peverell's grave in Godric's Hollow, Hermione asks if there is any connection with the Peverell family. Xenophilius says Ignotus is believed to be one of the brothers in the story. Harry privately recalls hearing the Peverell name somewhere else.
While Xenophilius prepares dinner, the Trio discuss the three Hallows. Hermione admits the wand has the best documented history. Magical history has many stories of super-powerful wands, and there seems to be a consistent link following one such wand nearly to the present. The Resurrection Stone is dismissed as being a misinterpreted Philosopher's Stone, but the Invisibility Cloak could be the one in Harry's pocket. It has withstood the test of time, unlike ordinary invisibility cloaks that eventually become threadbare and lose their effectiveness.
Harry goes into Luna's bedroom and notices that it is dusty and appears unused; Luna should be home for the holidays and is supposedly fishing. Harry again asks Xenophilius about Luna's whereabouts and why there are only four plates set for dinner. Xenophilius tries to prevent the Trio from leaving, then admits that "they" took Luna away as a punishment for his stories in "The Quibbler". Hermione spots approaching broomsticks; Xenophilius draws his wand, but Harry pushes the other two aside. The spell hits the Erumpent horn hanging on the wall, which explodes, blowing Xenophilius down the stairs, while the printing press drops across the staircase. Downstairs, two Death Eaters, Travers and Selwyn, demand to know why Xeno summoned them and tried to blow them up. Upstairs, Hermione tosses the Invisibility Cloak over Ron, then fires a Memory charm at Xeno as he claws his way through the rubble. She blasts a hole through the floor. As they fall, Harry sees the Death Eaters. Hermione safely Disapparates them to a field.
Analysis.
In addition to seeking information regarding the Deathly Hallows, the Trio also came here because Xenophilius Lovegood is sympathetic, publicly, to Harry's cause. However, we see that Death Eaters have forced him to abandon this support by imprisoning his daughter, Luna. Controlling family members via state-ordered or state-backed kidnapping is common in totalitarian regimes throughout history. Considering how dangerous it is for anyone to support Harry, it is questionable as to why Xeno continued publishing "The Quibbler" openly at his home rather than hiding underground like so many other wizard families, or why Luna was allowed to remain at Hogwarts, which is now under Voldemort's control. But like Luna, Xeno's odd views and outlandish beliefs have warped his perception of reality, and he may simply have been oblivious to the perils, or believed he was immune to any danger. Unfortunately, this has cost his daughter's freedom, and possibly her life (and threatens his own) if he fails to cooperate with Voldemort's Death Eaters. Now Xeno will do anything to save his only child, including betraying Harry Potter. 
Viktor Krum and others believe the Deathly Hallows symbol is a Dark mark. It is possible that most people, including Krum, never understanding its true meaning or origin, associate it with evil only because Grindelwald adopted it, and, after disgracing himself at Durmstrang, went on to become one of history's most notorious wizards. From then on, the Deathly Hallows symbol was forever tainted and considered "Dark." That a benign image can become associated with evil is hardly unprecedented. The Nazi swastika is such a modern-day icon: its origins actually date back to ancient history as a benevolent and sacred symbol in many Asian and Middle Eastern religions such as Hinduism, Buddhism, and others. It is because it is also linked to ancient Indo-European people, including the Aryans, that Nazi Germany adopted it in the mid-20th century as their emblem to represent racial purity and superiority. Although Asian cultures still consider it a symbol for luck, fortune, and victory, the swastika is primarily remembered (and still utilized) in the West to symbolize white supremacy and prejudice. Presumably, this same pattern has resulted in many wizarding realms associating the Hallows mark with Grindelwald, just as the skull and snake Dark mark represents Voldemort, though that particular symbol had no prior benevolent connotation.
Harry now knows what the Deathly Hallows actually are, but it will take him time to completely understand their significance. The Invisibility Cloak is likely the same one that Harry owns, supporting the belief that the other Deathly Hallows exist. In particular, the Elder Wand likely has some real existence, as is shown by the documented murders that apparently follow its nearly-cohesive trail. If the Elder Wand truly exists, and Harry finds it and wins its allegiance, it could be a powerful weapon against Voldemort. Harry is once again cast into confusion; whoever controls all three Hallows is supposedly "the master of Death." Dumbledore tasked Harry to find and destroy the remaining Horcruxes; would possessing all three Hallows make that task easier? Should he devote his energies to uniting the Hallows and thus possibly avoiding the almost certain death he faces at Voldemort's wand? Neither Harry, or we, have the answers to these questions.
Greater Picture.
The Deathly Hallows that Xenophilius Lovegood mentions are real, though it is unlikely that there could be three brothers who literally tricked Death. It is believed they may be based on the Peverells, a family that both Harry and Voldemort may be descended from; it is suggested that they could be simply extremely talented wizards. Meanwhile, we will learn that the artifact Voldemort has been seeking is actually one of the Hallows, namely the Elder Wand. It is currently publicly unknown where the Elder Wand is, but it will be discovered that it was in Dumbledore's possession at his death. Voldemort will discover this and retrieve the wand from Dumbledore's tomb. As legend proclaims this wand unbeatable in duels, Voldemort believes it will overpower Harry, as his own wand and Lucius Malfoy's were unable to. However, the story of the Three Brothers tells us that the Elder Wand's master is always vulnerable to defeat, and this is how Dumbledore not only came to possess it, but also lost its allegiance. Although Harry does not actually obtain the Elder Wand until the war's end, it will still prove to be a powerful weapon against Voldemort, for reasons that have yet to be explained.
Harry, as mentioned, seems to recall hearing the Peverell name somewhere. He will eventually remember that the ring Marvolo Gaunt brandished under Bob Ogden's nose in a memory Harry experienced in Dumbledore's Pensieve was "the ring of the Peverells". Harry has seen this ring on Tom Riddle's finger in a memory retrieved from Professor Slughorn, on Dumbledore's damaged hand when he collects Harry in the summer, and lying on Dumbledore's work table. Where it is now, and what significance it has, are as yet unknown; but Harry, remembering the ring, will come to believe that the symbol of the Hallows is scribed on it, and will begin to believe that the stone in the ring is the Resurrection Stone. It will turn out that he is correct, and that, unknown to him, he is carrying the ring with him; but the ring will not be revealed to him until he has already come to terms with death, thus mastering it.
Hermione, even under pressure, reacts with great intelligence and forethought at this chapter's end. With only moments to act, she protects both the Weasley family and Xeno, while also whisking Harry, Ron, and herself away to safety. She explains in the next chapter that, by allowing the Death Eaters to see her and Harry, she protects Xeno by confirming that he sent a legitimate summons. She also uses the Invisibility Cloak to hide Ron's presence from the Death Eaters (and presumably from Xeno with the Memory Charm as well), to protect him and also his family. If Ron is discovered with Harry and Hermione, rather than confined at home with Spattergroit, Voldemort and his Death Eaters will target the Weasley family, just as they did the Lovegoods. Concealing Ron safeguards his cover provided by the Ghoul. Hermione's family is also in danger, but she has hidden them in Australia, with new identities and altered memories.