John Wick is a movie about how its title character, played by Keanu Reeves, takes gleefully violent revenge on what might be scientifically designated a shit-ton of Russian gangsters after one of them kills the puppy given to him by his late wife. But more than that, it's a movie that takes the whole "one last job/retired/I got out" theme to its extreme end.
Plenty of movies suggest there's brisk business to be had for highly trained professional killers, but John Wick offers up a highly entertaining portrait of a deeply involved and surprisingly organized criminal underground that apparently demands full commitment — one that John left when he met the woman he married. "Have you returned to the fold?" "You working again?" everyone asks when they see him after an apparent five-year absence in the real world. It's just like when you go back to visit an old office, except with more people trying to murder you.