Out of the dozens and dozens of theories surrounding the death of Sirius Black, all of them generally assume that both of Bellatrix's spells were Stunners. However, not only the Stunner spell has a red colored jet of light, and the second jet of light Bellatrix sends at him is not mentioned as having any particular color. Before delving into the Veil in question, I'd like to try and clear up what everyone seems to believe - that the veil, and not Bellatrix, killed Sirius.
To refresh everyone's memory, here is the segment of OoP in question:
(Pages 805/806, American Version)
" Only one couple were still battling, apparantly unaware of the new arrival. Harry saw Sirius duck Bellatrix's jet of red light: He was laughing at her: "Come on, you can do better than that!" he yelled, his voice echoing around the cavernous room.
The second jet of light hit him squarely on the chest.
The laughter had not quite died from his face, but his eyes widened in shock.
Harry released Neville, though he was unaware of doing so. He was jumping down the steps again, pulling out his wand, as Dumbledore turned to the dais too.
It seemed to take Sirius an age to fall. His body curved in a graceful arc as he sank backward through the ragged veil hanging from the arch...
And Harry saw the look of mingled fear and surprise on his godfather's wasted, once-handsome face, as he fell through the ancient doorway and disappeared behind the veil, which fluttered for a moment as though in a high wind and then fell back into place.
Harry heard Bellatrix's triumphant scream, but knew it meant nothing - Sirius had only just fallen through the archway, he would reappear from the other side any second.
But Sirius did not reappear. "
Now that you've all read and re-read this excerpt, I want to point out several portions of it.
"Harry saw Sirius duck Bellatrix's jet of red light: He was laughing at her: "Come on, you can do better than that!" he yelled, his voice echoing around the cavernous room.
The second jet of light hit him squarely on the chest.
The laughter had not quite died from his face, but his eyes widened in shock."
Now, we all know that Bellatrix's first spell resulted in a jet of red light nearly missing Sirius. Most people choose to assume that it's a Stunner, which would result in the victim being knocked unconscious. However, the Stunner is not the only spell that results in red light.
In the Chamber of Secrets, in the Dueling Club chapter, we have this line (Page 190, American version):
".. Snape cried: "Expelliarmus!" There was a dazzling flash of scarlet light and Lockhart was blasted off his feet: ... "
Notice the color of the Disarming Charm is described as 'scarlet' - which is another word for 'red'. So far, two of the spells Harry has come into contact with both have jets of red light as their signature 'color', if you will. Incidentally, the color green is not only reserved for the Avada Kedavra curse.
Chamber of Secrets, page 112:
"A loud bang echoed around the stadium and a jet of green light shot out of the wrong end of Ron's wand, hitting him in the stomach and sending him reeling backwards onto the grass."
We know from fake Moody's class, that an inexperienced attempt at the Avada Kedavra curse will not harm the victim.
Obviously, as Ron is a second year here, AND he'd never cast any Unforgivable curse, he is not using the Killing Curse.
There aren't an unlimited amount of colors in the world, so of course the colors red and green will be repeated in hundreds of other spells.
It is indeed safe to assume that the wizarding world requires the knowledge of hundreds, if not thousands of different spells for a witch or wizard's everyday life. A specialized profession (like Death Eater or Auror, most prominently) would know even more spells that normal witches or wizards would not know.
It is impossible that the only three spells Death Eaters use are the Imperius, Cruciatus, and Killing Curse. As the Muggle world has a wide variety of ways to kill, torture, and dehumanize another human being, the Death Eaters most likely have a wide variety of spells in their arsenal. Indeed, one of the newer spells Harry sees in the Department of Mysteries is the 'purple jet of flame' that Dolohov used to attack Hermione. It's effect, judging from Hermione's tenderness in her ribs and abdomen and her having to take ten different types of potion to manage it, most probably did some damage to her internal organs, most notably in the region of her chest (her lungs, protected by the ribcage.)
Logically, someone like Bellatrix would not use a simple Stunner or Disarming charm to fend off an Auror or member of the Order. In addition, it was her cousin, the black sheep of the Black family (no pun intended) that had forsaken the family tradition of dabbling in the Dark Arts and was a - gasp - Gryffindor that grew up to detest them, despite everything Sirius' family tried to do to convince him otherwise. He was even friends with James Potter (marked for death by Voldemort, and sire to the boy marked as Voldemort's 'equal), Remus Lupin (a werewolf, which is an inferior "half breed" according to Sirius' mother), and Peter Pettigrew (we don't know very much about him, but there was probably reason for the rest of the Black family to dislike him.)
There is a definite bitterness and loosely disguised hatred in Sirius' tone whenever he talks about his cousin, so Bellatrix most probably felt that same dislike for him. Why use something so basic as a Stunner, which would only knock him unconscious? She more that likely used some sort of spell at the Death Eaters' arsenal, like the unnamed spell that Dolohov used, to try and take down Sirius Black.
Additonally, when a person is knocked unconscious, their eyes close and they slump to the ground like a stone. Sirius eyes, which Harry remembered plainly, were wide open, staring, and with a mingled expression of surprise and fear. Those are classic signs of the Killing Curse, Avada Kedavra.
Other victims of the Killing Curse, as mentioned in the books:
Goblet of Fire, page 4. Chapter: The Riddle House.
"... The doctors did note (as though determined to find something wrong with the bodies) that each of the Riddles had a look of terror upon his or her face - but, as the frustrated police said, whoever heard of three people being frightened to death? "
Goblet of Fire, page 216. Chapter: The Unforgivable Curses.
"So that was how his parents had died.. exactly like that spider. Had they been unblemished and unmarked too? Had they simply seen the flash of green light and heard the rush of speeding death, before life was wiped from their bodies?"
Goblet of Fire, page 638. Chapter: Flesh, Blood, and Bone:
"For a second that contained an eternity, Harry stared into Cedric's face, at his open gray eyes, blank and expressionless as the windows of a deserted house, at his half-open mouth, which looked slightly surprised.. "
Back to the lines describing Sirius' death:
-" The laughter had not quite died from his face, but his eyes widened in shock. "
- " It seemed to take Sirius an age to fall. His body curved in a graceful arc as he sank backward through the ragged veil hanging from the arch..."
" And Harry saw the look of mingled fear and surprise on his godfather's wasted, once-handsome face, as he fell through the ancient doorway and disappeared behind the veil, which fluttered for a moment as though in a high wind and then fell back into place."
All of the signs of death, as expressed by the three Riddles, Cedric Diggory, and Sirius Black, all describe the same things.
Their facial expression is said to be 'surprised' and 'terrified/fearful' in appearance. The rush of impending death coming at you along with that infamous flash of green light would terrify anyone, and take you by surprise as no one expects to be murdered.
Especially Sirius, who was notoriously hard-headed, stubborn, and a risk-taker.
An unconscious body, as I stated earlier, will slump to the ground in a certain way. A dead body with the life being rushed out of it by a green light, will probably arc backwards just as Sirius' did. His eyes were also wide open, staring, and slightly fearful; they would have been closed if it was a Stunner.
Even in the heat of battle, Sirius dared Bellatrix to "do better" than the first spell she shot at him.
Which leads me back to the opening sentences:
"Only one couple were still battling, apparantly unaware of the new arrival. Harry saw Sirius duck Bellatrix's jet of red light: He was laughing at her: "Come on, you can do better than that!" he yelled, his voice echoing around the cavernous room.
The second jet of light hit him squarely on the chest."
Sirius dared Bellatrix to do better than the first spell, so what would be better than sending the ultimate in spells, the Killing Curse, to take his life?
Now, about the archway. "But Sirius fell through it and he's dead!" is what everyone cries out.
I do believe that the archway is a portal to the world 'beyond' that of life, the place where the souls of the living pass through to rest for all of eternity. Much like how the ancient greeks believed that the souls of the dead all passed through to the underworld, the Veil acts as the gateway between life and death. It ties into the underlying thread of how Harry and Luna can see thestrals, and the both of them are able to hear voices 'beyond the veil'. It is undoutable that Harry heard James and Lily, and Luna heard her mother. Does the Veil only bring forth our parents that have passed on, or would Harry be able to 'hear' his other murdered relatives? That's a plausible question, as Luna is only mentioned to have lost her mother. That in itself can be something to discuss about the veil - what spirits of our loved ones choose to 'pass through'? Would only the strongest in our lives (.i.e.: our mother and father) be able to 'reach out' to those that are living that they left behind, even with the simple act of their voices being filtered through that veil? None of the others with them can hear the voices. Everyone in life loses someone in their family; Ron even said that there was an Uncle of his that died. So, shouldn't Ron at least be able to hear his uncle, or other family members that had passed on?
Or, does hearing people beyond the Veil have the same criteria as seeing thestrals? Do you have to fully accept the death of a loved one, or see them die, to be able to hear them? Hopefully, J.K. Rowling will elaborate more on the Veil in books six and seven, as the entire Death Chamber is one of the more interesting rooms illustrated in the entire series. I would enjoy reading about the other Department of Mysteries rooms as well, they seem highly fascinating - but that's getting well off track from this discussion.
The big question centers around the theory that the Veil is not only a gateway to the 'other world', but can also result in someone instantly dying if they 'pass through' it. Rowling has neither confirmed or denied this, unfortunately, and there is little in the fifth book that can solidify either of these theories. The characters are able to sense something 'not quite right' about the Veil, a sense of foreboding and ingrained understanding that the Veil is more than meets the eye. I really don't think that Bellatrix knew what the Veil was, or if she did, didn't completely understand it. She doesn't seem like the most intellectual of people, and she was entombed in Azkaban for quite a number of years. I highly doubt, in the heat of battle, that she was plotting how to lure him to the archway, and then find someway to get him to fall inside it - this assuming that the Veil is what kills and not a spell (Which is the popular belief of most Potter readers.)
" Harry heard Bellatrix's triumphant scream.."
Bellatrix screamed in triumph right after she hit him with the spell. The adrenaline of the moment, and shooting the Killing Curse at her cousin, would bring forth a triumphant scream - knocking someone unconscious and having some ancient veil do your dirty work would more than likely bring out disappointment over triumph. Bellatrix is the type of person that wants full credit for all that she does, and to be Voldemort's most beloved Death Eater. Killing Sirius herself, with a spell, especially since he's an Order member, would make her more elevated a death eater in Voldemort's eyes. Him dying by the circumstances of the veil, would not bring Bellatrix more notice by Voldemort as she wouldn't have directly murdered Sirius.
So, basically, what this essay sums up is the following:
- Sirius Black was murdered by Bellatrix Lestrange's Killing Curse.
- The Veil is a portal to the 'thereafter', but was not the direct cause of Sirius' death - Bellatrix is the clearcut murderer, with her spell.
- The ancient archway does filter some 'activity' from those beyond it, more than likely extremely close loved ones - which is why Luna and Harry heard it while the others did not.