Early in "Saltburn," students played by Barry Keoghan and Archie Madekwe disagree about which is more important: what an essay says or how it says it. Keoghan plays the protagonist, Oliver, so "Saltburn" seems to agree with him that it's substance but the movie is stronger on style.

Emerald Fennell's second film — she won an Oscar for writing "Promising Young Woman" — mashes up "Brideshead Revisited," "The Great Gatsby," "The Talented Mr. Ripley" and "Teorema."

As in "Promising," she wants to shock us into reconsidering things we believe to be true. She underscores that by taking big chances on the look of the movie, which include chopping a single dialogue scene into tiny pieces that are set in different places and feature different costumes, framing scenes in windows or mirrors and swooshing camera moves that emphasize the surreality of the story.

Oliver doesn't say much about his life before boarding school, other than to hint at abuse and poverty. He quickly falls under the spell of charismatic Felix (Jacob Elordi, from "Priscilla" and "Euphoria"), who invites him to visit his family's estate, Saltburn, with his dotty father (Richard E. Grant), troubled sister (Alison Oliver) and blithe, sarcastic mother (Rosamund Pike), who says of a friend's death, "She'll do anything for attention."

Fennell has a lot on her mind in the peripatetic "Saltburn" even if, as in "Promising," her ideas aren't as edgy as she thinks. Class, race and mental illness are hinted at in the satire, which climaxes at a disastrous "Midsummer Night's Dream"-themed party. But there's a difference between taking big swings, which Fennell does, and having big ideas, which I'm not so sure about.

The people all are so (deliberately) unpleasant that it's difficult to tell what Fennell is getting at, especially since she reconfigures characters to try to shift our feelings about them. Pike, for instance, is a less sympathetic "Absolutely Fabulous" lush in the early scenes but, later, Fennell wants us to feel for her and she becomes another character entirely. If the idea is that we're initially seeing her through Oliver's eyes and only seeing the real person later, that's not clear.

"Saltburn," like "Promising," aims for complexity but sometimes it's just muddled.

Even so, "Saltburn" is filled with ideas and it's never dull. Fennell is fantastic with the actors, particularly Keoghan, who played a similar role in "The Killing of a Sacred Deer" and earned an Oscar nomination for a completely dissimilar role in "The Banshees of Inisherin." His character is an enigma, even at the end, and the actor leans into that by convincing us Oliver can be all things to all people — sexy one minute, repellent the next, kind one minute, vicious immediately after that.

I've seen Keoghan in many movies but I barely recognized him in "Saltburn." It's a high-wire act and, even if "Saltburn" isn't always sure what it's doing, Keoghan never misses a beat.

'Saltburn'
*** out of 4 stars
Rated: R for graphic nudity, strong language, drug use and violence.
Where: In theaters.