WMG / Se7en

The film takes place in Gotham City.

It's a geographically indeterminate urban sprawl which vaguely resembles New York and/or Chicago, dark, gothic & decaying, in which it seems to be constantly night and/or raining, not to mention its populace seems about as damned as that of Gotham.

• Yes, of course! The events in the movie took place before Batman was born (or was still in the process of completing his training). And Somerset did stick around like he said at the end of the movie; he just changed his name to Lucius Fox.
  • And one day, defying all current medical knowledge, Sloth walked quietly out of the central hospital with a smile on his face. He carved it there himself.
    • Or maybe it was Mills having left Arkham during the mass riots? The Glasgow Grin was souvenir of a prison fight, and he attacked nearly everyone close to Batman EXCEPT for Lucius Fox, perhaps out of respect for his former partner and mentor?
    • Sloth didn't give himself a Glasgow Grin, in actuality he was given an experimental muscle growth treatment to cure his severe malnourishment and it worked far too well.
• You've all got it wrong. The Joker was really... the Lust victim! Think about it. What is it in The Dark Knight that the Joker keeps doing? He puts people in situations where they have to kill someone else to live. Which is exactly what happened to the Lust guy. He went looking for a whore, found one, then John Doe showed up. He put a gun to his head, strapped a knife to his cock, and said, "I'm going to shoot you unless you fuck her to death." And he did. He clearly wasn't dealing with it very well in the immediate aftermath (and hey, why would?). It's very possible that he could have looked at his choices and realized that everyone was kidding themselves. That everyone thought they were so civilized, when he knows deep down, when push comes to shove, "they'll eat each other." So he goes out to prove they will.
  • The scars? Probably self-inflicted for added horror effect.
    • Word of God on the DVD commentary says it's Walker's "love letter to New York." He wrote the film during a thoroughly depressing stay in the city writing exploitation screenplays.

John Doe is actually an Author Avatar

Think about the various speeches he gives about his work. How it will be studied and followed forever. Fincher's basically goating to the audience through John Doe, telling us that his work (i.e. the movie) will be remembered forever. And I can't disagree with him.

• Except of course that Andrew Kevin Walker wrote the film.
  • "We don't have an article named Andrew Kevin Walker". I see what you did there...

Mills is gonna be killed in jail by his Wrath to complete the plan.

Because of his anger he will end up in a fight with a fellow prisoner or a guard and be killed.

• Don't cops in jail usually go to Protective Custody?
  • Yes and no. Depending on their conviction, they may not be permitted Protective Custody, but with Mills he undoubtedly will be afforded this courtesy. However, this is only protection against Gen Pop, not guards who may be bribed or emotionally compromised. And there have been deaths during prison riots...a true act of Wrath, if ever there was one...

The victims were actually homonculi

John Doe is actually an alchemist, who discovered these homonculi living in the world. They lost their memories, powers, and regeneration abilities because something happened to them, and he decides to kill them in creative ways

John Doe was Keyser Soze

The entire Envy persona was all an elaborate ruse for some goal the audience wasn't privvy to. His death was faked, or maybe not depending on how far ahead of the game he was.

That it wasn't Tracy's head in the box, but Mills unborn/aborted child.

The reason why Somerset has to pause because it takes a while to see what he's looking at.

• I had actually thought that was supposed to be the original ending and they changed it at the last minute? Don't know where I got that idea from, I can't find any sources, but it seems to make more sense. The implication being that, as per her discussion with Somerset, Tracy was going to have the abortion and didn't tell Mills about it (which is why he didn't know). This would make her guilty of a sin— uber Christian Doe can't possibly be the type to let the sin of abortion go unpunished— so Doe performed the abortion himself, so to speak, as poetic punishment. I thought they changed it because they didn't want the implication to arise that Tracy was going to go through with the abortion and therefore make her Not Really An Innocent Woman After All, so they switched it to her head to take out that subtext that she was actually going to abort.
  • Gross as that sounds, it's never come up anywhere. It was always the "head in a box" movie.

Detective Mills eventually got acquitted sometime after this movie

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The head in the box was just a Halloween prop

• Killing Tracy makes no sense in the pattern of Doe's internal logic and given the progression of the case, he presumably wouldn't have even known she existed until a few days earlier, while he'd been planning things (and presumably picking victims) for at least a year. Maybe Doe really did intend for himself to be the Envy victim, but it also seems possible that he might have wanted to deliberately bait whatever cop arrested him into killing him, maybe just due to feeling the police force in general was guilty of the sin of wrath, guessed Mills potential Berserk Button, maybe spied on Tracy long enough to find out a couple of details to sell his story (like watching her buy a baby book or something), and put a fake head in the box.
• Additional points:
  • The blood could be from any of the previous victims.
  • John Doe is known to have done business with a specialty service, a leatherworker, for the Lust strap-on. As alluded to above, he also spied on and secretly photographed the victims. Not too much of a reach to think he could have taken a few candid photos of Tracy and given them to a propmaker to make a custom head.
  • In this scenario, Mills's wrath would have been completely unwarranted, making his actions potentially more tragic and serving as some sort of commentary from John on how wasteful and pointless such anger is.
  • Mentioning Tracy was pregnant could have been just an extra twist of the knife if John had no idea if it was true. He has a 50/50 chance of being right, there's no real penalty for him being wrong, and it's certainly an incendiary claim that could push Mills over the edge.