Summary of Memento by a film critic.

As I mentioned above, asserting that "Memento" is a tale told backward is actually superficial -- even misleading. Nolan has in fact done something more complicated and way more clever than that. The shocking opening credit sequence, in which Leonard kills a corrupt cop named Teddy (Joe Pantoliano, the ubiquitous master of sleazebag characters, who played Ralphie on "The Sopranos" this year), is the only scene that literally runs backward: In it, we see a Polaroid photo undevelop, a bullet fly back up the barrel of a gun and Teddy come back to life briefly "after" the sound of the shot.

This scene, which is in color, is immediately followed by a black-and-white bit in which we see Leonard, in an anonymous motel room, explaining a little about his circumstances in voice-over. The next extended scene, back to color, finds Leonard meeting Teddy at his motel and then traveling to an abandoned building, whereupon we see Leonard shoot Teddy again. (This time it's even more disturbing.)

The movie then proceeds, alternating black-and-white and color sequences. The main narrative of the story is the backward, color one. We stumble back in increments, and meet "new" characters -- Teddy; a classic noir moll, Natalie; her boyfriend Jimmy; and a drug dealer named Dodd -- each scene stepping back to put the previous one a bit better in context and providing a lot of shocks, jokes and horrors along the way. And in between each we see Leonard back in his hotel room, in black and white, talking on the phone and telling an oddly parallel story.

Here's what we figure out as we go: Leonard Shelby (Pearce) is a former insurance investigator. In his previous life, intruders rape and kill his wife one night. He kills one of them, but the other bonks him on the head and gets away. The injury leaves him suffering from a condition called anterograde amnesia, which means that he can't create new long-term memories. Leonard can remember everything prior to the accident, since his old long-term memories are still intact; but his current attention span lasts roughly 15 minutes (and even less when he's stressed or distracted), and in no case can any of these current memories be permanently implanted in his brain.

Since he can't experience the passage of time, his wife's death is always fresh to him; and so he is passionately determined to find the remaining intruder and kill him. He reminds himself of what he's doing through a series of notes, a pocketful of Polaroid snapshots with helpful information written on them and (for really important stuff) tattoos. We see that he's developed a number of clues to the killer's identity, each of these burned onto his body. The killer's name is John or James and his last name begins with a "G." He's a drug dealer; Leonard even has the killer's license-plate number. As the movie lurches backward, we see how and where he gleans each piece of the puzzle.

At the same time, the black-and-white scenes, which run in forward order, find Leonard in his hotel room talking on the phone. In these sequences, Leonard tells that parallel tale, illustrated for us with visual "flashbacks." As an insurance investigator, Leonard had a curious case: a man, Sammy Jankis, who had an accident and wound up with, yes, anterograde amnesia. Leonard investigates and ruthlessly denies the man's medical claim on the grounds that it was a mental problem and not a physical one.

But Sammy's wife can't deal with the condition: She doesn't quite understand Leonard's ruling and think it means Sammy is in a sense faking. She suffers from diabetes, and it's Sammy's job to deliver her insulin shots. So taking advantage of Sammy's memory problem, and knowing that her husband loves her and wouldn't do anything to hurt her, she asks him to give her three or four insulin shots in quick succession. In doing so, she has the satisfaction, as she sinks into an irreparable coma, of proving to herself that his condition must be real.

But it's important to remember that this Gothic noir is dribbled out to us, largely in voice-over, in short black-and-white scenes in chronological order that alternate with the much more kinetic and confusing main backward story line, which is told in color.

The first of the film's cosmic jokes is revealed in the final color scene (which is of course the first scene chronologically of the color story). We see Leonard kill Jimmy, who we know is Natalie's boyfriend; with this act, Leonard thinks he's killed the man who killed his wife. But then Teddy appears to articulate something we're just beginning to understand: Leonard has already tracked down his wife's killer: He just doesn't remember it. It's one of "Memento's" delicious ironies that the avenging murder we've already seen Leonard accomplish is different from the one Teddy's talking about, but the net effect is the same: to give us a sudden and monstrous realization of Leonard's sanguinary condition.

Teddy even shows Leonard a Polaroid of Leonard, bloodied but beamingly happy, pointing proudly to an empty, untattooed spot on his breast, where we know he wants to imprint the news that he finally avenged his wife's death. Teddy says he'd taken the photo right after the deed to give Leonard evidence that he'd achieved his desired revenge.

Teddy explains to Leonard that he has manipulated Leonard to kill Jimmy and possibly several other similarly loathsome bottom feeders before that. He says something to the effect that it was "to give you something to live for"; of course, Teddy also has to admit that his own motivation had a little bit to do with the $200,000 in drug money stashed in the trunk of Jimmy's Jaguar.

Leonard gets angry, and Teddy, apparently frustrated by his lack of memory, hits him hard with some uncomfortable truths: Leonard's wife hadn't even died, Teddy tells Leonard. She actually survived the assault. Leonard himself had killed her, by administering insulin shots. The Sammy Jankis business is a dreamy conflation of a real story with events from Leonard's own marriage, events so horrifying and guilt-causing that Leonard has had to project them onto someone else -- poor, hapless Sammy Jankis.

This astonishing scene at once solves one part of the movie's puzzle but creates a new one in its place. For the first, we understand that Nolan has upended the conventions of the film noir, in which a flawed hero tries to find some measure of justice in an unjust world. Leonard has suddenly become an Everyman in a potentially infinite purgatory, blindly trying to revenge an act that has already been avenged, and finding himself manipulated, over and over, by people who would use a splendidly configured avenger for their own ends. (It has been hinted along the way that even Teddy's death may be the handiwork of another manipulator, with a few hints pointing at Natalie as the possible perpetrator.)

Nolan lets us bask in this revelation for all of a minute before unleashing another cosmic joke.

Leonard, having learned this, struggles to deal with it. He knows he won't be able to remember what Teddy is telling him. So he empties his gun, to fool himself into thinking he hadn't used it. He burns the bloody and triumphant photo of himself. He pulls out a Polaroid of Teddy and writes on it: "DON'T BELIEVE HIS LIES"; and he copies down Teddy's license-plate number. He drives off to have the number tattooed on his leg as a clue to help himself track down the killer later. In effect, he turns himself into a time bomb, ready to go off when, at a period sometime in the future that he won't be able to appreciate fully, he will finally "solve" his wife's murder again, and wreak vengeance on Teddy.

In the end, "Memento" rights itself, and the wronged will somehow be avenged, in a corrupt way that is the only way to achieve justice in a corrupt world.

Right? Perhaps.

Once you see "Memento" a couple of times, you figure out the devilish scheme Nolan has constructed. Here's how I think it works. If we give letters to the backward color scenes and numbers to the monochrome scenes, then what Nolan presents us with is this:

Credits, 1, V, 2, U, 3, T, 4, S, 5, R, 6, Q ... all the way to 20, C, 21, B, and, finally, a scene I'm going to call 22/A, for reasons I'll explain in a minute.

What is beautifully clever here is that black-and-white scene 22, the last sequence in the film, almost imperceptibly slips into color and, in an almost vertiginous intellectual loop, becomes (in real-world order) scene A, the first of the color scenes: This then serves as the link between the forward progression of black-and-white material and the backwardly presented color stuff.

Even neater is that Nolan shoots this in such a way that very few viewers notice the switchover: Leonard enters a dark building; after some crucial action, he takes a Polaroid; as he shakes the photo and the Polaroid's color image fades in, so does the color of the entire scene.

So, if you want to look at the story as it would actually transpire chronologically, rather than in the disjointed way Nolan presents it -- oh, will this ever be fun to do on DVD! -- you would watch the black-and-white scenes in the same order (1 to 21), followed by the black-and-white/color transition scene (22/A). You would then have to watch the remaining color scenes in reverse order, from B up to V, finishing with the opening credit sequence, in which we see Teddy meet his maker at Leonard's hands:

1, 2, 3 ,4 ,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22/A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V.

Reading the film this way, here's what happens in real-world chronology. While things may seem confusing when you first watch the film, Nolan has been very careful to make sure that, when reassembled, everything in the main part of the film -- everyone's behavior and motivations -- makes perfect sense.

Leonard has been sitting around room 21 at the Discount Inn, poring over police files, trying to locate his wife's killer. He's talking on the phone, explaining his condition to someone on the phone. He relates the story of Sammy Jankis. Then he gets paranoid and hangs up the phone. But the person on the phone is persistent, even slipping notes under his door. The motel clerk finally tells him there's a guy, a cop, waiting in the lobby for him. Leonard relents and goes out to meet him. It's Teddy. We now understand that this is all a routine that Teddy has undergone with Leonard many times before.

Teddy's in the midst of a manipulative plan to have Leonard kill Jimmy Grantz, a local drug dealer. He gives Leonard the address of an abandoned building where Jimmy, who Teddy claims is the murderer Leonard is looking for, is due to arrive. Leonard, wearing blue jeans and driving a pickup, drives off, with Teddy following a few minutes behind.

At the building, Leonard kills Jimmy. He switches into Jimmy's clothes and takes his car keys. Teddy arrives and throws water on Leonard's triumph: You've already tracked down your wife's killers, he tells him; you just forgot. There's no such person as Sammy Jankis. Leonard's a mental case, Teddy tells him frankly. Teddy wants the $200,000 that he knows is in Jimmy's trunk.

The pissed-off Leonard decides to manipulate himself, setting up Teddy as his next suspect; he writes himself a note, identifying Teddy's license-plate number as belonging to his wife's killer. Leonard drives to the nearest tattoo parlor to get the number tattooed on his thigh. Teddy follows him there and tries to get Jimmy's car keys from him. (He wants that two hundred grand in the trunk.)

Leonard sneaks away, still wearing Jimmy's threads; by now he has no idea when or where he got these clothes or this spiffy car. But he finds a note in Jimmy's pocket and, assuming it's meant for him, he heads for Ferdy's bar to meet Jimmy's girlfriend, Natalie (Carrie-Anne Moss). Natalie sees the car pull up and is surprised that the driver isn't Jimmy. Leonard enters the bar. Natalie's heard of a guy with Leonard's condition hanging around. After testing his disability, in an unappetizing fashion, she's persuaded that he's is on the level, and takes him to her house.

After he watches TV and consults his notes for a few hours, Natalie returns. She surreptitiously hides all the pens and pencils in the room and then starts insulting Leonard, provoking him until he punches her. While Leonard desperately searches for some way to write a note to himself about what has just happened, Natalie goes outside, sits in her car and smirks. After a few minutes, she slams the car door, knocking Leonard's concentration off track, and reenters, crying about how someone named Dodd has beaten her up.

Moved, Leonard agrees to defend her from this supposed batterer. She writes a description of Dodd for him. He gets in the car to go after Dodd, but is immediately distracted: Teddy is waiting for him in the car. Teddy tells him not to trust Natalie and suggests that he stay elsewhere. He recommends the Discount Inn. Leonard has now forgotten about the Dodd business and, more amusingly, has also forgotten that he's already checked in at the Discount Inn, in room 21. Friendly, greedy desk clerk Burt gladly rents him room 304 as well.

Leonard sets up shop in 304 and calls an escort service for a hooker. He has her try to re-create the scene from the night he and his wife were attacked. He discharges her and drives to a trashy construction site, where he ruminates about his marriage and burns some of his wife's belongings. He stays there all night. As he leaves the construction site in the morning, Jimmy's car is spotted by Dodd -- a drug dealer who was Jimmy's boss. Wanting to know what's become of Jimmy -- and the money he was carrying -- Dodd gives chase.

Leonard slips away and goes to Dodd's motel room -- Natalie had given him the address -- and waits for Dodd to arrive. But he forgets where he is and why, assuming it's his own motel room. When Dodd shows up, Leonard mistakes him for an intruder and beats him up and tosses him in a closet. Desperate, he calls the only phone number he can find -- Teddy's. Teddy comes over and together they send Dodd packing. Teddy again makes efforts to get access to the keys to Jimmy's car.

Knowing from his notes that his run-in with Dodd had something to do with Natalie, the agitated Leonard goes back to her place, demanding an explanation. She placates him, agrees to help him identify the owner of the license-plate number on his thigh and takes him to bed. The next morning, they agree to meet for lunch, after Natalie has had a chance to look up the license number. Leonard forgets to take his motel key and leaves, but Teddy is waiting for him. They go have lunch, after which Leonard returns to the Discount Inn. Realizing he doesn't have a key, he asks Burt to let him in. Burt takes him to room 21 instead of room 304, and Leonard realizes he's being ripped off. But before Leonard returns to 304, he finds his note about having lunch with Natalie and dashes off to see what info she has for him. After some banter, Natalie gives him the DMV information, fingering Teddy as the killer -- just as Leonard had planned.

He goes back to his room and calls Teddy, telling him to come right over. At the front desk he tells Burt to let him know if Teddy shows up, but Teddy gets there while they're talking. Leonard drives Teddy out to the same location where he killed Jimmy -- having gotten the address from Natalie -- takes him inside the building and shoots him. It's the same shooting that we saw in reverse during the opening credits.

On this level, "Memento" is a persuasive piece of work -- a seemingly straightforward murder mystery that ends up turning the genre inside out. But what has seized the attention of its fans is yet another level of meaning that Nolan seems to be working on. Throughout, the film features visual hints -- some so brief as to verge on the subliminal -- that call everything else in the film into question.

For one, as Leonard narrates the conclusion of the Sammy Jankis story, we see a serene, extended shot of poor Sammy in an insane asylum. A figure walks across the front of the camera -- and suddenly, for literally a split second of screen time, we see Leonard himself in Sammy's chair. Similarly, as Teddy berates Leonard at the abandoned building, we see shots of Leonard himself administering insulin to his wife's thigh. But a split second later, we see him merely pinching that same thigh -- a "memory" that we have seen before.

In the film's final sequence -- the bravura 22/A -- as Leonard drives around in a frenzy of mental activity, we see a rushed glimpse of him relaxing in bed with his wife -- with the legend "I'VE DONE IT" tattooed on his breast.

These scenes call into question the film's back story -- everything that happens "before" the black-and-white scenes. No matter how jumbled the movie's chronology is, everything I've described in the narrative above is stuff that we in the audience actually see. It may be confusing, and we have good reason to doubt that anyone is ever telling the truth, but we see what we see. We have no reason to doubt the accuracy of what transpires. But the back story is presented to us in flashbacks, flashbacks from the memory of a man with brain damage.

We are told by Leonard -- who, remember, is a less-than-reliable, brain-damaged source of neurological information -- that, in his form of amnesia, his recall of his previous life is left intact. Even if we accept that, there's no reason to believe that "intact" is the same thing as "accurate." This point may be the source of a number of odd, unanswered questions: Leonard has a copy of a police report, but we are given to understand that some pages are missing. Presumably the missing pages would have included the information that Leonard's wife didn't die in the original attack. But who took the pages? And why?

It seems that Teddy's outburst at Leonard in scene 22/A answers all the film's questions. But if what Teddy says about Leonard is true, and if Leonard can remember fully his life before the attacks, why doesn't Leonard remember his wife had diabetes? He says flatly that she didn't. If she didn't, then Teddy's not telling the truth.

And what's the thematic point of the Sammy story in the first place? Is it a hint that Leonard's condition may not be real? As Leonard tells the tale, the crucial point is whether Sammy had suffered physical brain damage or if his affliction was somehow psychological. In the end, has Nolan taken refuge in a new version of that hoary thriller cliché, "It was all a dream"? Are the confusing final scenes just evidence of Leonard's brain synapses misfiring as he sits in the asylum?

On the other hand, what's the point of a good movie about memory if you don't leave a few things up for grabs? As Leonard himself tells Teddy fairly early on, "Memory's unreliable ... Memory's not perfect. It's not even that good. Ask the police; eyewitness testimony is unreliable ... Memory can change the shape of a room or the color of a car. It's an interpretation, not a record. Memories can be changed or distorted, and they're irrelevant if you have the facts." This is the very heart of the film. "Memento" is a movie largely about memory -- the ways in which it defines identity, how it's necessary to determine moral behavior and yet how terribly unreliable it is, despite its crucial role in our experience of the world.

In its own weird way, it's also a tribute to grief. Grief is an emotion largely based on memory, of course. It is one of "Memento's" brilliant tangential themes that relief from grief is dependent on memory as well -- and that is one of the chief hells our unfathomable hero is subjected to. "How am I supposed to heal if I can't feel time?" Leonard asks.

Still, even after so many viewings, after reading the script and discussing the film for months, I haven't been able to come up with the "truth" about what transpired prior to the film's action. Every explanation seems to involve some breach of the apparent "rules" of Leonard's disability -- not merely the rules as he explains them, but the rules as we witness them operating throughout most of the film.

The scene of him and his wife in bed, the triumphant tattoo on his breast, can't be a flashback. We've seen already that he doesn't have the tattoo, so he can't have had it in the past. How can he remember lying in bed with his living wife, with the tattoo "John G. raped and killed my wife" visible on his chest? It has to be a fantasy, which would make sense in the context. He thinks he has just avenged her (or has just set in motion a plan to avenge her). He's visualizing his own sense of satisfaction and peace.

Did Sammy kill his wife with insulin? Or did Leonard? For Leonard to have killed his wife and then have transferred the story onto Sammy (as Teddy claims) would require that Leonard remember an event that happened after his accident. Yes, Leonard has a quick memory flash of injecting his wife, but it's followed by a repetition of an earlier version of the memory, where he was merely pinching her. So, of course, the injection memory is just the other memory distorted by Teddy's suggestion.

Except, several hours later in the chronology -- which is to say earlier in the film -- Leonard, sitting at Natalie's house, has another momentary memory flash of preparing the injection. (It appears to be the exact same shot as before.) Even if the image was a false one, influenced by what Teddy said, how can Leonard still remember it hours later?

Who ends up in the mental hospital? Well, Leonard tells us that Sammy ends up there. But Teddy tells us that Leonard's nuts, and then there's that flash in which we see Leonard himself there. And Jonathan Nolan's authorized Web site -- which apparently counts as part of the official canon -- is unambiguous about Leonard being an escapee from an asylum.

Is there an answer? I don't know. Christopher Nolan claims there is one. In an article in New Times Los Angeles on March 15, Scott Timberg writes: "Nolan, for his part, won't tell. When asked about the film's outcome, he goes on about ambiguity and subjectivity, but insists he knows the movie's Truth -- who's good, who's bad, who can be trusted and who can't -- and insists that close viewing will reveal all."

But, at this point, I no longer believe him. The only way to reconcile everything is to assume huge inconsistencies in the nature of Leonard's disorder. In fact, in real life, such inconsistencies apparently exist, if Oliver Sacks is to be believed. But to build the plot around them without giving us some hints seems like dirty pool.

Still, even if it turns out that Nolan has cheated like a two-bit grifter in fashioning his story, "Memento" remains an extraordinary achievement. Not only has he devised a film that challenges its audience, demanding the sort of attention and thought that Hollywood would never ask of viewers, but he has used his cleverness to stir up questions and feelings about the most basic issues of how we experience reality. In addition to being a puzzle, "Memento" is a philosophical tragedy that considers issues the makers of "Pearl Harbor" could never dream of.