The red pill or the blue pill?

That question, posed in "The Matrix," is so last century. In "Limitless," a nifty, stylish little exercise in drug-fueled paranoia from director Neil Burger, it's the clear pill that raises a different question: If the apple from the tree of knowledge fell right into your lap, would you take a bite? And then what would you do?

The apple in this case is an illicit designer drug, NZT, and thirtysomething slacker Eddie Mora (Bradley Cooper) — a divorced writer with a terminal case of writer's block, a guy who was just dumped by his most recent girlfriend (Abbie Cornish) because he's going nowhere at the speed of light — finds himself in possession of a stash of the stuff. Now, NZT isn't just another quick high. Instead, as Eddie finds out, it makes a lie of the old saying that we only use 20 percent of our brains and cranks that percentage up to 100.

Suddenly, Eddie — seducing the worlds of writing, women and Wall Street — has massive amounts of game and brains, attracting the attention of barons of the boardroom such as Carl Van Loon (Robert De Niro), bullies on the street such as Russian mobster Gennady (Andrew Howard) and some mysterious third guy who keeps giving him the side eye and chasing him around Manhattan.

And did someone mention side effects? Baby, this apple bites back. This is where Eddie might be starting to realize that getting really smart really quickly might have been a dumb thing to do.

It's good to see Cooper — usually seen in raunch ("The Hangover") and rom-coms — stretching and not just skating by on his looks. By contrast, De Niro merely has to look pained much of the time.

Based on the novel "The Dark Fields" by Alan Glynn, "Limitless" is directed with a nimble efficiency and sense of visual humor by Burger that is at times reminiscent of the work of Danny Boyle ("127 Hours").

"Limitless" never takes itself too seriously but still manages to be suspenseful and clever.

Burger has opened up what was a very interior book and injected it with a jolt of cinematic electricity. Smart move, smart movie.

"Limitless"

Our grade: B

Genres: Thriller, Action

Running Time: 97 min

MPAA rating: PG-13

Release Date: Mar 18, 2011