It is not explicitly stated in the novel what form this attack took, but Percival is given a life sentence in Azkaban for tracking down and hexing the boys who traumatised his daughter. To prevent her being institutionalised in St. Mungo's Hospital, or hurting someone accidentally with her uncontrolled magic, Kendra moves the family to Godric's Hollow, and conceals Ariana's illness. Their wizarding neighbours and acquaintances assumed that Ariana is a non-magical squib, and that Kendra is hiding her out of shame. When Dumbledore and his friend Elphias Doge leave Hogwarts at the age of 18, they plan to take their "then-traditional" tour of the world. On the eve of their trip, however, Ariana accidentally kills Kendra during one of her uncontrolled outbursts of magic. Because Dumbledore's parents are absent (his father in Azkaban and his mother dead), he becomes the head of the family and it becomes his duty to put food on the table, as the family's misfortunes have left them poor. He is forced to remain in his house with Ariana while Aberforth completes his education. Aberforth knows of his brother's resentment and offers to care for Ariana himself, claiming that she prefers him to Albus, but Albus refuses, stating that it is his duty as the eldest child to care for the family. When Gellert Grindelwald arrives at Godric's Hollow, he and Dumbledore become immediate friends, and the two dream of a new world order in which wizards rule over Muggles "for the greater good". Dumbledore and Grindelwald suggest that they have to leave the Dumbledore home to carry on their plans, but Aberforth protested against this, as Ariana's condition would not allow her to be moved. The ensuing argument between Albus, Aberforth and Grindelwald turns into a duel, and as Ariana becomes more and more stimulated, she is caught in the crossfire and killed - though neither Albus nor Aberforth are sure whether one of them or Grindlewald caused her death. Stricken with grief and remorse, Dumbledore breaks ties with Grindelwald for good. According to the author, as a result of this, Dumbledore's boggart becomes Ariana's corpse. In Philosopher's Stone, he also mentions to Harry that the deepest desire of his heart, revealed by the Mirror of Erised, is to have a pair of woollen socks, but in the seventh novel, Harry realises that he and Dumbledore see the same thing in the Mirror: their