At one point in “Sharper,” someone observes that it’s easier to get people to accept a lie if they don’t see the lie coming.

This same observation applies to the experience of the film itself, which centers on a series of cons and swindles. The first time it happens, the audience isn’t ready for it, and it’s a shock. The second time it happens, we see it coming, but the script pulls a three-card monte on us, and we end up fooled anyway. But by the very last con, we see it from a mile off, and we start to wonder why the marks are suddenly more stupid than we are.

So “Sharper” is mostly enjoyable, entertaining from start to finish — and it even has its interpersonal details worked out nicely. It’s just that in the last 10 minutes, after cruising along, some of the air goes out of the tires.

What’s missing might have been impossible to provide: Something to transcend everything that went before. If a whole audience is looking for a con, you can try to con them anyway. But you can also try something else entirely, something nobody is thinking of.

This is so easy for a critic to say, especially as I have no idea how the movie should have gone. But if a whole audience is looking in the same direction for the big surprise, it seems to me that there’s an opportunity to sneak up from the other side.

“Sharper” refers to a kind of person who lives on their wits. But in the early going, it’s something else, a story of young romance.

It’s a bright afternoon in New York City. Tom (Justice Smith) is reading a book in his empty bookstore when suddenlyshewalks in. Sandra (Briana Middleton) is a graduate student working on her doctoral thesis about feminism and the Black experience, and she’s looking for a book by Zora Neale Hurston. Immediately, Tom is interested and asks her to dinner.

It seems too good to be true. This is the woman of his dreams. Dimly, we might wonder, what’s in it for her? He does seem a bit out of her league, but not terribly, and there’s such a thing as getting lucky. Really, their only problem is that she has a scary brother who always needs money, but you can’t have everything perfect.

And that’s the last thing you’re going to hear about the story.

In due time, we have a chance to become interested in other characters — Julianne Moore as the smiling, maternal girlfriend of an old billionaire (a sly John Lithgow), and Sebastian Stan, virtually channeling Joe Pantoliano as a slippery con artist.

“尖锐”是如此构建良好和铆接(mostly) that it more than survives being structured into separate episodes. First, we follow one character, then another, then another — and sometimes this involves going back in time. That’s OK. The movie builds up a desire on the part of the audience to see all the details filled in.

“Sharper” works like a machine, and so it seems unfair to complain that, by the end, it feels too mechanical. It’s fun. It should have beenmorefun, but take the fun where you can get it.

Reach Mick LaSalle: mlasalle@sfchronicle.com