There's really only one word to summarize this movie, and that one word is clearly obvious: Khan.
But I'm getting ahead of myself, so let's start from the beginning.
Star Trek: Into Darkness (2013) is the second installment of the movie reboot of one of the most well-known science fiction franchises in the known universe. Now, as a non-Trekkie, I had gone into Star Trek (2009) with no expectations and very little proper Trek knowledge. Heck, my sister made fun of me when I was surprised that there were many "Spocks" running around in the film (I've since known that they are called Vulcans, so stop laughing). I did, however, enjoy Star Trek, so was not against seeing another movie should the occasion call for it.
When I heard rumors that Benedict Cumberbatch (start of BBC's Sherlock, a show I absolutely adore) was to star as the villain in the next Star Trek film, I immediately decided that yes, I was going to watch it at the local theater. And boy, when Cumberbatch plays villain, he does it to the utmost perfection.
Into Darkness continues the adventures of the Enterprise, a starship captained by James T. Kirk (Chris Pine) and helmed by various alien characters. The character reintroduction comes off as an explosive start, with Kirk, Spock (Zachary Quinto), and Dr. Leonard McCoy (Karl Urban) running across a foreign planet in hopes of saving it from a catastrophic volcanic eruption. This attempt at saving lives brings about trouble, as once more, Kirk's lack of care of his crew's safety puts his captaincy in jeopardy. However, when Kirk loses a loved one due to an attack by the renegade operative Khan, all chips are down, and the Enterprise transforms from a harmless exploration vessel to that of a weaponized starship.
Now, as I understand it, Into Darkness is a rebooted retelling of Star Trek II: The Wrath of Khan (1982). Those who've actually seen the 1982 movie had expected the death of a particular Vulcan character; however, while the character of Khan and several scenes were pulled from the original, the storyline was clearly different, and as a villain, Khan was not without his motivations. Oh, and while there were particularly poignant similarities, it's safe to say that there is no requirement to watch The Wrath of Khan to understand what Into Darkness is all about.
I was actually glad that the familiar characters remained as they were in Into Darkness, particularly because I thought their dynamic was fantastic. The Spock-Kirk duo was once again pretty strong in this film, and if you've seen the end of the movie, you might be able to understand why I'd be so moved by it. Granted, I think I'd read into some of the subtle elements in the film, so I wasn't too worried over anyone in particular.
Then, of course, there was Khan (Cumberbatch) himself. He was a splendid villain, with a mixture of brilliance, physical prowess, and utter psychosis. Throughout the film, Khan had likened himself to Kirk, and understandably so, because both characters care much about their crew. However, the film called for a villain, and Khan's insanity clearly shows through in his methods and his actions. Never mind that I found him particularly attractive, but that's the impeccable Cumberbatch acting for you... So yes, needless to say, Star Trek: Into Darkness was a fantastic movie.