Dumbledore’s lack of concern
Today was not a good day for Albus Percival Wulfric Brian Dumbledore. Everything seemed to be going his way at the start. The students were full of cheer. Halloween decorations were up all over the great hall, not Samhain honorings, and children were excited for the feast. Finally, people would not be focused on the old ways the school would be truly open to muggleborns. None of that honoring and communing with the dead nonsense. If you could truly commune with the dead Ariana would have responded to his summons. At least one time!
The feast had been a smash hit though there were some sugar highs. How could he not feel Severus’ glare when the tables filled with all that lovely candy. It was just so nice to have all these kids pumped on sugar instead of around a bonfire eating livestock and offering sacrifices. That was barbaric. Anything involving a Sacrifice should be confined to the last century in Albus’ not-so-humble opinion. Making contact with aos sí could be dangerous; they were a totally different brand of spirit. And sacrifices made for powerful magic. That power was too dangerous for anyone but the Albus Percival Wulfric Brian Dumbledore! They could not be trusted to control the power which came from such an experience. Much better to enjoy their Halloween candy inside.
He was so glad to finally have enough control over his precious Hogwarts to fully make the conversion away from giving power to questionable hands. A sugar high was much more manageable and less risky.
After the feast, he was thoroughly happy, the elves had put some lemon drops by his plate, and then he entered his office to a disaster. Two of his monitoring devices had broken! The wards had fallen at the Dursley residence, and Harry's tracker had been disabled. When he arrived at the Dursleys it just got worse. Petunia was in serious shock not even really acknowledging him when he arrived. That did not bode well. Was that blood he smelled? Albus’ heart rate started to increase. Was Harry dead? What about the prophecy? Nothing to do but open the master bedroom.
Bood, guts, two legs on opposite sides of the room. But even in such a state dismemberment this was obviously an adult's body. Vernon Dursley had been brutally murdered. And there were traces of apparition, but they were too faint to follow. Who could do something this heinous? Albus had to assume that Harry had been kidnapped, likely by one or more death eaters. Who else would kill a muggle point blank range with an explosion spell? Only death eaters would treat a human this way. Muggles were just cute children who needed to be shown the way by their superiors after all. The only thing to do was put Snape on it. He had promised to protect Harry. This was something he could trust the spy with. His vow meant that he would take looking seriously.
The only thing keeping Albus from despairing completely was the tracker that informed him of Harry’s heartbeat. The location might be broken but at least the heartbeat was clearly still alive, and didn’t seem in any particular distress. Should Albus notify the Ministry? The aurors would be useful, but if he was found, it would be a free for all as to who would get custody. And Albus couldn’t risk someone like Lucius Malfoy getting it. James and Lily would never forgive him. And Harry was too important, what with the prophecy not being entirely fulfilled yet. But on the other hand, maybe this was part of the prophecy?
Harry “couldn’t live” properly, that is to say, with his family, while Voldemort survived? Every child wanted to live with their family. That's why wizard law gave custody to godparents that went through a ritual and then to blood relatives with priority given to wizard blood. Maybe Harry had to have this happen because of the prophecy.
Without any leads, Albus couldn’t really do anything but wait. A week before the boy’s 11th birthday, they would get an address from the Book of Names. Now what to do about this situation?
It did not occur to Dumbledore to look at how Harry had lived with his family. His assumptions were a good enough explanation for him. He didn’t ask to see Harry's room or scan either muggles' memories, which may have given him some clue. He just vanished the traces of Vernon Dursley’s murder and made up some documents such as a death certificate, so Petunia could go through normal muggle procedures. No police would need to get involved. Officially, Vernon had died from a heart attack. Unfortunate, but given his weight and general level of health and fitness… nobody questioned it. Petunia in her shock and grief was almost grateful to the freak who defied her. She was more grateful that officially, Harry had been placed with other relatives in a different part of the country. No need for the muggle authorities to worry about him.
Petunia was most grateful for the fact that Dudley had been Trick-or-treating with Piers and his mother at the time. Dudley had seen neither the body nor the mess, and was sad, but not traumatized. It did help Dudley realize his weight was a problem. And so Dudley started to ask his homeroom teacher about healthy eating and sports. The teacher took him to the school nurse, who invited a dietician. They worked together with the PE teacher, and Dudley started to improve, especially after they invited Petunia to explain to her that giving Dudley lots of food all the time was not showing him love. She was killing him. Petunia was deeply shocked, and worked with the dietician and Dudley to change things.
They did, and so, for Petunia and Dudley, Vernon’s death had a positive impact. The life insurance from Vernon’s company was generous, and Petunia wasn’t worried about the future. All in all, her life was a lot better. She wouldn’t say so aloud, but her marriage hadn’t been overly happy. And it had been made worse by the added stress of having to take in her freakish nephew. Now that he was gone, it might even have worked out better with Vernon, but if she was honest… she didn’t miss her husband. Dudley sometimes missed his dad, but never for long. Ultimately, Dudley was selfish, and didn’t really care for anyone but himself.