There's Great Acting, and then...
Whenever I discover a great actor, I have a twinge of fear that he or she can do what Elijah does - that I'll find out that Elijah's not unique. The latest person to cause me this fear is Benedict Cumberbatch. If you don't recognize the name, you must have missed Sherlock, the most recent Sherlock Holmes series to hit Masterpiece Mystery. As can be determined through a couple of the essays on this site, I'm a long-time fan of the original, so it might seem strange that I'd thoroughly enjoy a version set in the 21st century but, well, strange things do happen. And Mr. Cumberbatch's presence and acting as the title character has a lot to do with my appreciation. He's very good at showing nuanced emotions, and is a master of tiny changes in facial expression (including some great eyebrow acting). After multiple viewings of the first season's three episodes, though, I feel safe in saying that everything he does is under conscious control. Which means he doesn't do what Elijah does. The emotions may be nuanced, but they're not a completely realistic mix of a half-dozen emotions all at once. The tiny changes in facial expression aren't microexpressions - they're very much under his control. We don't have a case of someone getting so tuned into a character that he shows us even that character's unconscious and uncontrollable emotional expressions.
The spot that had me most fearful is the very end of episode three - a terrific high-tension moment that's left as a cliffhanger. Wanna see it? I just got my DVD.