‘But I didn't,’ muttered Harry.

‘But I didn't,’ muttered Harry. He said it aloud to try and ease the dead weight of guilt inside him: a confession must surely relieve some of the terrible pressure squeezing his heart. ‘I didn't practise, I didn't bother, I could've stopped myself having those dreams, Hermione kept telling me to do it, if I had he'd never have been able to show me where to go, and—Sirius wouldn't—Sirius wouldn't—’

Something was erupting inside Harry's head: a need to justify himself, to explain—

‘I tried to check he'd really taken Sirius, I went to Umbridge's office, I spoke to Kreacher in the fire and he said Sirius wasn't there, he said he'd gone!’

‘Kreacher lied,’ said Dumbledore calmly. ‘You are not his master, he could lie to you without even needing to punish himself. Kreacher intended you to go to the Ministry of Magic.’

‘He—he sent me on purpose?’

‘Oh yes. Kreacher, I am afraid, has been serving more than one master for months.’

‘How?’ said Harry blankly. ‘He hasn't been out of Grimmauld Place for years.’

‘Kreacher seized his opportunity shortly before Christmas,’ said Dumbledore, ‘when Sirius, apparently, shouted at him to “get out". He took Sirius at his word, and interpreted this as an order to leave the house. He went to the only Black family member for whom he had any respect left ... Black's cousin Narcissa, sister of Bellatrix and wife of Lucius Malfoy.’

‘How do you know all this?’ Harry said. His heart was beating very fast. He felt sick. He remembered worrying about Kreacher's odd absence over Christmas, remembered him turning up again in the attic ...

‘Kreacher told me last night,’ said Dumbledore. ‘You see, when you gave Professor Snape that cryptic warning, he realised that you had had a vision of Sirius trapped in the bowels of the Department of Mysteries. He, like you, attempted to contact Sirius at once. I should explain that members of the Order of the Phoenix have more reliable methods of communicating than the fire in Dolores Umbridge's office. Professor Snape found that Sirius was alive and safe in Grimmauld Place.

‘When, however, you did not return from your trip into the Forest with Dolores Umbridge, Professor Snape grew worried that you still believed Sirius to be a captive of Lord Voldemort's. He alerted certain Order members at once.’

Dumbledore heaved a great sigh and continued, ‘Alastor Moody, Nymphadora Tonks, Kingsley Shacklebolt and Remus Lupin were at Headquarters when he made contact. All agreed to go to your aid at once. Professor Snape requested that Sirius remain behind, as he needed somebody to remain at Headquarters to tell me what had happened, for I was due there at any moment. In the meantime he, Professor Snape, intended to search the Forest for you.

‘But Sirius did not wish to remain behind while the others went to search for you. He delegated to Kreacher the task of telling me what had happened. And so it was that when I arrived in Grimmauld Place shortly after they had all left for the Ministry, it was the elf who told me—laughing fit to burst—where Sirius had gone.’

‘He was laughing?’ said Harry in a hollow voice.