I just got back from seeing The Dangerous Lives of Altar Boys and found it one of the more disturbing movies I've ever seen. It starts off feeling like a fairly happy movie about a group of 14-year-old Catholic friends, but almost immediately starts hinting that it will not stay this way. And it doesn't. I counted three plot twists that shocked and surprised me and made me think, "That's not supposed to happen in this kind of movie!" Without giving the plot away, I'll reveal that two of these moments occur when a certain character reveals things about their life to another, and the third involves sudden violence.
Fascinatingly, the plot outline on the IMDb entirely ignores much of the plot and merely notes, "A group of Catholic school friends, after being caught drawing an obscene comic book, plan a heist that will outdo their previous prank and make them local legends." While the comedy this outline suggests is present in the movie, it's not the most interesting part. In fact, there are three more interesting elements. The first is the plot twists mentioned above, which are thought-provoking as well as disturbing (the two going together as they often do). The second is the way in which the movie works through themes of faith, relationships (both friendly and romantic), and how one maintains and questions each in the face of great challenges. It also deals with the definition of sin and refers several times to William Blake and his poem "The Tyger," the theme of which the movie reflects. The third great element of the movie is the excellent use of animated sequences depicting the characters as superheros and villians. These capture the emotions of Francis, the main character, perfectly, and make the movie unlike any other in style, as well as themes.
Now for the factual part: The Dangerous Lives of Altar Boys is based on a book by Chris Furhman and directed by Peter Care. The lead actors are Emile Hirsch as Francis Doyle, Kieran Culkin as Tim Sullivan, Jena Malone as Margie Flynn, and Jodie Foster, who also produced the movie, as Sister Assumpta. All four contribute excellent performances. The movie is rated R in the United States for "language, sexual content and youth substance use." It was released in 2002.