There are so many twists and turns to Steven Soderbergh’s deceptively lighthearted dark comedy The Informant! that by the time the end credits roll, it’s hard to recall that it all began with orange juice, maple syrup, biodegradable trash bags, jumbo shrimp and chickens.

What do all these things have in common? Corn. Maple syrup and orange juice? Corn syrup. Trash bags? Corn starch makes them biodegradable. Chicken? Feed them lysine, an amino acid derived from corn, and they go to market in six months instead of eight. Jumbo shrimp? Take a guess.

“Corn goes in one end,” Marc Whitacre (Matt Damon) confides in an inner monologue voice-over as he walks the office floors of Archer Daniels Midland, “and profit comes out the other.”

Whitacre was a divisional president at ADM in charge of bioresearch in the early 1990s, and if you haven’t read Kurt Eichenwald’s The Informant: A True Story, on which the film is based, and don’t otherwise know Whitacre’s story, don’t Google him if you’re planning on seeing the film (and watch out for reviews, many of which reveal too much).

It’s better to let the tale progress on the screen like a multicourse meal at an unfamiliar restaurant.

All I will say is that, from the corn thing, The Informant! descends into a complex web of international corporate crime, whistle-blowing and a lengthy, covert federal investigation. It’s part Erin Brokovich or The Insider big-business malfeasance and whistle-blowing, part breezy Catch Me if You Can or Burn After Reading caper comedy, with a bouncy score by Marvin Hamlisch and 1960s-esque title captions.

There’s a lot to chew on. Still, there is a moment when Whitacre comes face to face with a plate of puffy jumbo shrimp and the whole premise of putting corn in everything is more than enough to give you pause, with or without criminal profiteering.

On the other hand, who wants to give up $27 trays of 50 jumbo shrimp at Costco? Bring on the corn.

Whitacre’s internal monologue is a brilliant twist on a hackneyed narrative device. At times, he seems to be taking us into his confidence, explaining to us the inner workings of not only corporate success, but corporate malfeasance. It’s as if we were getting the voice-over from the tell-all memoir or exposé he never wrote.

But then at other times his thoughts merely flit randomly from one irrelevant topic to another, pondering the correct pronunciation of Porsche, the size of a co-worker’s paycheck, the unsavory vices of Japanese businessmen, and a possible premise for a TV show about a man pursuing his own doppelgänger.

It’s quirky and amusing: a Tarantino-esque stream of pointless dialogue internalized into stream of consciousness, peppered with pop-culture cross-references to the corporate thrillers of 1993, The Firm and Rising Sun.

But the moments Whitacre chooses for some of these meditations — in the midst of crucial meetings with corporate partners and FBI investigators — bespeaks a restless, isolated mind, withdrawn into itself, abstracted from the routines of daily life.

And then the other shoe drops, and we start to grasp that the explanatory intimations of his monologue aren’t just plot exposition, or after-the-fact exposé-style narration, but the narrative that Whitacre tells himself about his own life as he lives it.

Lonely, isolated people sometimes fill the psychic space around themselves by looking at the routines of their lives as if through the eyes of a stranger or someone unfamiliar with what they do — an absent family member, say, or a visitor from another country or even another era — and imaginatively proceed to show that other person around, explaining their lives to themselves as they would to someone else.

But how reliable is such self-explanation? Whitacre presents himself as Tom Cruise in The Firm; he sees himself as a hero, and there’s a case to be made that he is — and people willing to make that case.

As the movie tells it, the real hero could be Whitacre’s wife, Ginger (excellent Melanie Lynskey), who twists her husband’s arm to tell the nice FBI agent (Scott Bakula) what he knows, even threatening to tell him herself if he doesn’t, and who then stands by her man through thick and thin.

Although Whitacre jokingly assigns himself the code name “0014” because he’s “twice as smart as 007,” the character is light-years removed from a superspy — which, of course, is the point for Damon, coming off the Jason Bourne series.

With 30 extra pounds, an unglamorous moustache and an embarrassing hairpiece, Damon is a comedic natural as the sort of compromised schlub often played by William H. Macy, but with an extra spark of charisma and intelligence, which makes sense for a Ph.D. who became the youngest vice president in ADM history and pulled off, well, what happens in this movie — and, in the aftermath, went on to earn a pair of law degrees, among other things.

Toward the end of The Informant! is a crucial scene in which the walls are closing in and something unexpected happens to Whitacre’s interior monologue: It begins to converge with the actual discussion he is having.

In a disconcerting way, there is almost a disconnect as he begins thinking things before saying them and actually saying what he is thinking. And then comes a shattering question for which he has no answer — except the intractable truth.

Each of us would like to think that, in such situations as the movie poses, we would do the right thing; in moments of crisis, we tell ourselves that that is what we have done. The Informant! confronts us with the inveterate human capacity for self-justification and self-deception — and the extent to which we are all prone to casting ourselves as the hero of our own drama and the victim of our own tragedy.

Steven D. Greydanus is editor

and chief critic at DecentFilms.com.

Content Advisory: Limited profane language and a number of obscenities, brief crass remarks and language, and a comment about a perverted practice. Mature viewing.