Harry Brown is a different sort of "revenge" film. Just as Crazy Heart was made for Jeff Bridges, Harry Brown was made for Michael Caine. Without Caine, the plot is a bit harder to swallow and wouldn't come off other than a movie about a bulletproof vigilante with an itchy trigger finger.
Harry Brown (Caine) is a retired Royal Marine whose wife is in the hospital. He dutifully visits her every day, but is forced to take the long route to avoid the gangs who've turned the shorter route into a crime-ridden cesspool. One night, Harry gets the call that his wife is dying, only to arrive too late because he can't take the shorter route.
Harry is overcome by grief, and confides in his friend Leonard (David Bradley) his remorse over why he wasn't able to reach her in time. During the conversation, Leonard tells Harry he was also a victim of street violence and, as a result, has taken to carrying a bayonet for protection. Harry admonishes Leonard and suggests that he go to the police instead. Leonard disagrees and the two part ways.
The following day, Harry is visited by detectives investigating Leonard's murder. Harry knows what happened, but without evidence, he has a hard time convincing the police it wasn't justified homicide. The police found Len's bayonet and thugs could easily say they were defending themselves. With both his best friend and wife gone, Harry decides he has nothing to lose and fights back.
Michael Caine is Harry Brown. Without him, the movie wouldn't completely fall apart, but be much worse for wear. There's a "tough guy" element to his character, but Caine manages to bring a warmer, more human side to the character. He's out for vengeance, but there's an emotional resonance behind his actions that rarely comes out in this sort of film. The performance is really enough to help push through some of the film's messages, which otherwise wouldn't come across as effectively.
Most of Harry Brown's issues are editorial. Some scenes roll on for way too long. They're important scenes, but keep going after they make their point. In the end, they only slow down the movie's tempo. Moments are still suspenseful, but even edgier scenes are flat. Though it never disrupts the film's flow, it's enough to diminish any long-term impact.
The included commentary with Caine and director Daniel Barber (along with producer Kris Thykier) adds just a slight bit of edge back into the film, though viewers likely won't choose the audio commentary for their first viewing. Outside the commentary, there's little else included as far as extras beyond some deleted scenes. Additionally, there's little reason to chase down the Blu-ray version, unless you're picky about picture or just want the best available version.
Harry Brown is a great movie, though it gets there mostly on the back of Michael Caine. Still, despite its errors, it is a solid rental at the very least.