"It was me what rescued Harry from Lily an' James's house after they was killed! Jus' got him outta the ruins, poor little thing, with a great slash across his forehead, 'an his parents dead...an' Sirius Black turns up, on that flying' motorbike he used to ride. Never occurred to me what he was doin' there..."
     -- Rubeus Hagrid

• What really happened the night Lily and James died?
• timeline of events - October 31/November 1, 1981
• Priori Incantatem - the Wand Order problem

NOTE: According to JKR (Diane Rehm show, 10/20/99), "Voldemort killed James and Lily, then tried to kill Harry." This is clearly what she intends. It is not, however, what it actually says in the books. This page discusses what the actual text states and what that would mean. Clearly, JKR doesn't intend this to be the way the story goes. But this IS the way it's written. Also, yes, I am well aware of the fact that JKR has confirmed many months ago in an email that "Lily came out first." I, like many fans, don't like the messy way this mistake was "fixed," but that mystery is clearly solved. Many questions remain, however...

What did really happen?
So what really happened that Halloween in 1981? What was the order of events? Who was present? Who died and when? It is very difficult to answer these questions based on what we read in the books. We hear the official story from Voldemort himself, the version that everyone in the Wizarding community has accepted since that day, but since there are no witnesses that we know of, this is all assumptions. Voldemort assumes that he killed James and Lily, of course, and Harry assumes that the voices he hears when the Dementors are around are those of his parents. But we don't know for sure.

The evidence that we do have from the Priori Incantatem suggests that James and Lily were killed using Voldemort's wand AFTER Voldemort attacked Harry. After all, the last nine spells that wand cast included the ones that killed the Potters but DID NOT INCLUDE THE ONE THAT ATTACKED HARRY AND REBOUNDED ONTO VOLDEMORT. This mystery still remains, no matter in which order Lily and James came out of the wand. Who, if Voldemort was unable to cast a spell, killed James and Lily Potter?

Along with all that, another mystery confronts us: there does seem to be quite a chunk of time missing in the story. What happened AFTER Voldemort attacked Harry and before Hagrid turned up in Privet Drive a day later? The fact of the matter is that we just don't know. All we do know is that twenty-four hours after Voldemort showed up in Godric's Hollow, Hagrid brough the infant Harry Potter to Privet Drive, where McGonagall and Dumbledore were waiting. During that time, Sirius Black caught up with Pettigrew in a Muggle street with disasterous results (surprisingly, we don't hear mention of this on the Muggle news that night--"Fourteen Killed in Gas Main Explosion!"--but then we don't hear the whole broadcast).

Here's a timeline of those events as far as we can discern them. The facts as stated in the books are written on this timeline in black, with some commentary written in blue:

The Fidelius Charm is performed to hide the Potters from Voldemort. At the last minute, Peter Pettigrew is chosen to be their Secret Keeper instead of Sirius Black. No one besides the Potters and Sirius Black knows of the switch.

Voldemort, who has been told of the whereabouts of James and Lily Potter by Wormtail, comes to Godric's Hollow and to their house. It is evening. The house is destroyed at some point in the following, but we don't know when or how.

He is met at the door by someone - a man who looks like James Potter - who cries out to a woman that Voldemort is here and that he will hold him off. We do not know the outcome of this duel. (We are not told in the book the outcome of this battle, although the assumption is that James was killed by Voldemort)

The woman  runs away with Harry but Voldemort catches up with her. He tells her to step aside, but she insists on shielding Harry. The woman was almost certainly Lily Potter. 

Voldemort attempts to kill Harry Potter, but the spell backfires and the Dark Lord is hit. He is barely alive and his body is gone. He flees. (This spell never comes out of the wand, so we know that the spells that DO come out must have happened after this.)

Someone uses Voldemort's wand to kill first Lily, then James Potter. We do not know how soon after Voldemort's defeat this occurred. (Because of the objective record we have of spells cast by Voldemort's wand, we do know that Voldemort was in no condition to have cast these spells at this time. That leaves us wondering who killed James and Lily?)

Hagrid goes to Godric's Hollow and rescues Harry from the ruins of his parents' house before the Muggle officials arrive. He meets Sirius Black there and comforts him. Sirius gives Hagrid his flying motorcycle.

• The Wizarding Community begins to celebrate the downfall of Voldemort. They take to the streets, even though they are noticed by Muggles in their non-Muggle clothing, and owls fly everywhere as word spreads. 
• Minerva McGonangall encounters Hagrid early in the morning. He does not have Harry with him any more, apparently. Hagrid tells her very little of what's happened; all he tells her is that Dumbledore will be going to Number 4 Privet Drive later that day. She is not even informed at this point what the signifigance of that address is, since she is shocked later to discover that Dumbledore intends to leave Harry there and is not aware that those horrible Muggles are Harry's relatives. Hagrid also does not tell her that James and Lily were killed. She goes to Privet Drive quite early in the day in the form of a tabby cat and waits on a stone garden wall. Celebrations continue all day. She waits there until almost midnight
• Peter Pettigrew flees, pursued by Sirius Black. He is cornered in a Muggle street. Pettigrew puts his escape plan into action, shouting out so Muggles could hear "Lily and James, Sirius! How could you?" and then blasting a hole deep enough to crack open the sewer. Pettigrew turns into a rat and escapes into the sewer, leaving his finger behind. Sirius is blamed for betraying the Potters and for murdering Pettigrew and a bunch of Muggles. 
• A Junior Minister in the Department of Magical Catastrophies is first on the scene. His name is Cornelius Fudge. Twenty members of the Magical Enforcement Squad take Sirius Black into custody while Fudge sets about modifying memories of the witnesses.
• THE WHEREABOUTS OF HAGRID AND HARRY POTTER ALL DAY ARE NOT KNOWN.
• Almost at midnight, Dumbledore arrives in Privet Drive. He meets McGonagall and then greets Hagrid, who flies in on Sirius Black's motorcycle. He hands Harry over to Dumbledore to put on the Dursley's front step.
• Hagrid leaves to bring Black his motorcycle back, apparently unaware that Sirius has been arrested.

• Cruciatus Curse cast on Harry by Voldemort a few moments before (comes out as screams), June 24, 1995
• conjuring of a magical hand to replace the one Wormtail cut off, cast by Voldemort after regaining his full body, June 24, 1995
• Cruciatus Curse cast by Voldemort on Avery, June 24, 1995
• the murder of Cedric Diggory with the Killing Curse, cast by Wormtail on Voldemort's command, June 24, 1995
• Cruciatus Curse cast on Wormtail, witnessed by Harry in his dream, cast by Voldemort, exact date unknown, but somewhere around the last week of May, 1995
• the murder of Frank Bryce with the Killing Curse on the evening of August 20, 1994, cast by Voldemort in his "ugly baby" form, from his chair in the Riddle House
• the murder of Bertha Jorkins, exact spell inknown, cast by Voldemort, summer of 1994, some time before August 20
• the murder of James Potter, exact spell unknown, apparently cast by someone other than Voldemort and probably NOT at his direct command, on the evening of or sometime after October 31, 1981.
• the murder of Lily Potter, exact spell unknown, also apparently cast by someone other than Voldemort and probably not at his direct command, also on the evening of or sometime after October 31, 1981.

• the attempted murder of Harry Potter, a Killing Curse cast by Voldemort on the evening of October 31, 1981

a spell or spells cast against the people in the house in Godric's Hollow who tried to protect Harry, cast by Voldemort. If these people were in fact James and Lily, they were not killed at this time.