A Hollywood thriller due out this year centers on a young man who awakens while undergoing open-heart surgery but is unable to move or cry out. The film's plot will undoubtedly take many more dramatic turns from there, but its early premise is, sadly, not entirely far-fetched. Episodes of intraoperative awareness while under general anesthesia are reported by one or two of every 1,000 patients. In reality, such incidents are usually brief and generally do not involve pain or distress, but they do highlight one of several ways that even the newest generation of anesthetic drugs can sometimes leave much to be desired. Indeed, the medical specialty of anesthesiology has evolved into a sophisticated art form because scientific understanding of how anesthetic drugs actually work, and how to make them better, has lagged behind most other areas of drug development.