A strange thing happened while I was watching Star Trek Into Darkness, director JJ Abrams’ sequel to the 2009 reboot of the classic science-fiction franchise. While the frame fills explosions and mayhem, I realize the movie is more fun to think about than it is to watch. Abrams and his screenwriters accomplish something tricky: they include all manner of references to the original series; the character moments are well-earned; and the plot directly addresses Star Trek’s ongoing identity crisis. There are so many moving parts that it weighs down the whole. But while blockbusters are not successful when a set-piece unintentionally raises questions about the nature of entertainment, they’re at least interesting.