Max and his wife Michelle had a son, who looked just like him.  And they were in love.  One day Max came home and saw his house was broken into.  He killed two men he found upstairs and shot at one man who jumped through a window a disappeared.  His wife was dead on the bed and his child dead in the cradle.  After that he was a broken man.  BB tells Jim this so he understands where Max is coming from and tells him that Max is going off the deep end.

It's raining in an alley and Jason is getting drenched.  A limo pulls up and Jason gives Nicole Horne a file, it's Jack Lupino.  Nicole asks Jason if he's trying to blackmail her and Jason says no.  Nicole then orders Jason to take care of the problem.

Jason, still drenched, walks through the Aesir offices and gets his messages from his secretary who tells him a detective is waiting for him in his office.  Jason goes in to see Max looking at pictures of his wife and daughter and asks who he is.  When Max turns around, Jason apologies, saying that he didn't recognize him.  Max then asks Jason what his wife was working on and Jason, looking guilty, says that they don't keep files for that long.  Max then proceeds to beat him in his executive chair until he agrees to tell him everything as long as he's protected from the other person.  It was a drug that made 1% of the people superhuman and 99% of the people insane, seeing hallucinations and other crazy things.  Jason points to the folder that he showed Nicole and says that it's all in there, but he needs Max to protect him.  Meanwhile his secretary and other people are concerned, hearing his cries of pain when he was being beaten and call security.

Jim is also still in the building and watches as SWAT-like security people run through Aesir and decides to follow them.

When Max exits the office with Jason, the security person kills Jason and then tries to kill Max.  A bloodbath ensues where everyone is fair game if they get in between the security people and Max.  Max kills many of them, dives to get the envelope that is near Jason's dead body, and then runs away and into Jim.  Jim tells him to come in, but Max refuses.  Just when it looks as if something would happen between the two men, the wall explodes from the security people laying a charge and Max escapes.

Mona goes into her warehouse home and sees that it's been broken into.  She walks in carefully, gun first, to see Max sitting on her couch watching the promotional videos for Valkyr, a super drug for the military, obviously the cause of a lot of this.  Mona says that she can't help Max with Jack Lupino, it's too dangerous, she'll do anything, but not that.  Max replies that he'll do it and Mona asks him if he just wants to be killed because it'll reunite him with his family.  Max tells her that he really hopes that'll be how it works.

Jason is on top of Ragnarok and drinks some of Valkyr, roaring when it courses through him.

Max gets into the lower level of Ragnarok and goes on a shooting/killing rampage, taking down all the guards who are protecting what looks to be a huge scale production of Valkyr.  When he goes into a smaller office, Jack Lupino jumps down and starts fighting with him, obviously very strong and more powerful than Max.  He whispers that 'they' will have to choose whom they like best, him or Max.  Just when it starts looking very bad for Max, BB comes in and shoots Jack, killing him.

Max asks BB what is going on and that it wasn't Lupino who killed his wife because Max could tell Lupino had no idea who he was.  BB's second in command then lams him over the head and Max falls to the ground.

Max, BB and BB's second in command all are walking down to the river on the docks and BB reveals that he is the one who was behind everything.  He had Jack setup a huge distribution of Valkyr that was making oodles of money.  He had to tie up loose ends, so killed off Michelle - and he said that once he realized he could get away with that, he realized he could do anything.  BB then puts a couple of vials of Valkyr into Max's pocket, saying that it'll be seen as a suicide, that Max Payne was a junkie and finally took his own life.  They are about to tie a weight to his feet and throw him in when Max throws a few punches and escapes, diving into the water with BB and his 2nd shooting wildly and missing.  Finally BB says it's time to go and he'll freeze in the water anyways (ice is thickly covering most of the top of the river.)

We are now where the movie started.

Max has a flashback as he's drowning and sees his wife and child on the bed, alive and happy, but his wife's voice says, 'not yet.'  He then gets new energy and crawls to the dock, severely hypothermic and almost dead.  He pulls out the two vials of Valkyr and drinks them, suddenly feeling warm and the entire world seems to get turned into a blazing mess with the Valkyries flying overhead as the drug starts to affect him.

Jim starts a full-fledged investigation into his department, realizing that many people have been corrupted by Aesir and calls in the FBI.  One of the cops tells BB that the FBI is there and everything is going south.  BB flees down into the basement of Aesir where he is about to get into a car when people start getting shot, Max is still alive and killing everyone, so he and his second flee upstairs.  He calls Nicole and asks her for a helicopter on the top of Aesir, saying that the "Michelle Payne" incident has come back to them.  He tells his second to take C4 and cover the exit, blowing it so Max can't get up.

Max, meanwhile, is rampaging through the whole building, killing people without even seeing them first.  At the same time, he's seeing the wings and the Valkyries trying to swoop down and touch him and vacillates between being a hardcore killer and freaking out about all the fire and winged creatures that he's seeing through the ceiling and windows.  Mona finally pulls him out of a trance and gets him going again, saying he's not done yet and has to keep moving.

Jim is at the base of Aesir, having it surrounded by cops and tells them to find Max, but not to kill him.  They can hear gunfire and are trying to get up into Aesir.

Mona kills the 2nd in command, but he survives long enough to blow the C4 that explodes three floors of the building, causing a rain of glass and metal onto the cops below and also sends Max into a variety of hallucinations with the real fire interspersed with his visions.  Max makes it up to where BB is on the helipad; Nicole having ignored all his phone calls - leaving him for dead.  BB shoots him several times to no effect and then drops his gun, saying he'll give a confession.  Max ignores that and just shoots him.  After BB falls dead, Max goes to the tip of the helipad and kneels down, seeing the sunlight finally come up from the clouds.

He sees his wife and son again on the bed and goes to them, picking his son up, happy at last.  But again his wife's voice says "not yet."  It cuts back to him on the helipad on his knees with the cops surrounding him.

After the credits there is an extra where he goes into a bar and gets a beer, but the bartender gives him two and motions over to where Mona is waiting for him in a booth.  Mona says nothing, but passes over a newspaper that shows how strong Aesir is becoming and shows a picture of Nicole as the head.