It’s hard to believe you’d be squinting at your watch in the dark while two of the most charismatic actors in Hollywood are on the screen in front of you. But that’s how badly “Limitless” squanders the talent it’s assembled. Besides Bradley Cooper and Robert De Niro, the thriller also has a clever premise, thanks to its source material, the novel “The Dark Fields” by Alan Glynn. Eddie Morra (Cooper) is a scruffy starving artist. His successful girlfriend Lindy (Abbie Cornish) pays for lunch before dumping him because he seems to be going nowhere fast. He has a book contract, but hasn’t even written one word of his novel. (Never mind that a regular guy rarely gets a contract without having written the entire novel first — that’s the least of the implausibilities here.)

But Eddie soons finds the solution to writer’s block. He runs into his former brother-in-law, who’s moved up from dealing street drugs to serious pharmaceuticals. He gives Eddie a free sample of something called NZT. After one night on the drug, Eddie’s written a masterpiece — the words simply flow from his brain onto the page. Imagine what he could do with a steady supply. He tries to get more, but returns to find the man murdered. He discovers where the stash is hidden, though. But then the bad guys figure out that Eddie’s figured it out. Eddie then has a lot on his plate — learning how best to marshal his newfound hyperintelligence, winning his girlfriend back, and staying alive, not to mention finding a fresh supply when he runs out and the withdrawal effects kick in.