This evening I saw the movie Limitless at UA Cinemas, Times Square, Hong Kong. One of the movies from my Must See Movies list.
This movie has an original story. It is about a down and out writer who receives a custom drug from his ex-brother in-law, which helped pick himself out of his slump. He later finds out the drug is not as described by his dead in-law, and comes to the realization of its deadly effects.