After quite some time, Sirius finally came out of his long daze, though his expression was still pained.
He kept repeating the same words under his breath. "Regulus... How could you have been so stupid?"
At the same time, his gaze shifted to Kreacher, turning murderous.
Clearly, Sirius had blamed Kreacher for being the direct cause of Regulus's death.
If Professor Lupin hadn't reacted quickly enough to grab Sirius, his Cruciatus Curse would have hit Kreacher.
"Have you gone mad, Sirius?" Professor Lupin shouted, forcing him down into a chair.
"I'm not mad! Let go of me!" Sirius shot back without the slightest courtesy.
"That filthy, lowly house-elf didn't bring Regulus back and just let the Inferi drag him into the water!"
"Regulus could have been saved! It could have brought him back and kept him alive!"
"It was the one directly responsible for Regulus's death! I'll kill it—I'll torture it with my own hands, then kill it! I'll kill the beast!"
At some point, the velvet curtains had been drawn open. The portrait of Mrs. Black inside said nothing, silently listening to the conversation in the drawing room.
Another figure had appeared at the edge of the portrait: former Headmaster Phineas.
Clearly, there was also a portrait of him in Number 12 Grimmauld Place, allowing him to travel between portraits.
Now he, too, listened quietly to the conversation in the drawing room, his thoughts unknown.
When Kreacher heard Sirius's words, the last taut nerve in its mind snapped.
It fell to its knees again and burst into tears. Then, from who knew where, it pulled out a hammer, apparently intending to smash its own hand with it.
At the same time, it wailed through its tears as if possessed:
"...So it was old Kreacher's fault... Old Kreacher was the