Harry wakes up early thinking of [Dumbledore] and [Godric's Hollow], and finally decides to climb upstairs and have a look around.
Harry wanders through [number twelve, Grimmauld Place], realizing that someone has searched through it. Then, in Sirius's room, he finds relics of his parents - a picture of James, and part of a letter from Lily describing Harry's first birthday - and searches the room for the rest of the letter, wondering what it might say about [Dumbledore].
Hermione finds Harry in Sirius's bedroom, wondering where he's been. He shows her the letter from his mother and they wonder about [Bathilda Bagshot] and about the rumors they've heard about [Dumbledore], finally deciding to head down to breakfast.
While walking downstairs, Harry notices the sign on Regulus Black's bedroom - and suddenly realizes that he must be the mysterious [R.A.B.] When he, Hermione, and Ron search the bedroom, though, they turn up nothing - until Harry realizes that he has seen the locket before, while cleaning the drawing room, and they race downstairs to see whether Kreacher stole it.
Desperately wanting to find the [locket], Harry summmons Kreacher and asks him about it, barely ready for the story that follows. He learns that Voldemort forced Kreacher to drink the potion in the [cave] and left him for dead, infuriating Regulus; that Regulus returned with Kreacher, drinking the potion himself before being dragged into the lake of [Inferi]; and the Mundungus Fletcher has since stolen the true locket. As a token of gratitude, he gives Kreacher [Regulus's locket] and sends him off to find Mundungus.
As they wait for Kreacher to return, Harry, Ron, and Hermione notice Death Eaters congregating in Grimmauld Square. Meanwhile, Hermione continuously reads [The Tales of Beedle the Bard], while Ron plays with the [Deluminator] and Harry walks out in frustration.
Walking downstairs alone, Harry suddenly hears the door open - and Lupin walks in. After Harry confirms his identity, he, Ron, and Hermione tell Lupin all that's happened to them, and he updates them as well. He also shows Harry a [Daily Prophet] story labeling Harry as Wanted, and another describing the rounding up of [Muggle]-borns. Lupin then asks to accompany the trio, but Harry gets angry with him for deserting the now-pregnant Tonks, and Lupin storms out.