Brief - well as brief as I can make it - synopsis:
Story revolves around Walt who is an old (read: abrasive, obnoxious and extremely set in his 1960s (i.e. extremely racial) ways) who basically has no friends and has alienated himself from his family.
Walt befriends the neighbor's after neighbor's kid tries to steal his car as part of a gang initiation. When gang tries to recruit neighbor's kid to initiate him again, Walt gets involved because they got into his yard. After this, entire neighborhood begins to see Walt as a protector.
Of course gang seeks to get retaliation.
That's as brief as I can make it without giving away most of the movie - but it is worth admission price.