Sometimes a filmmaker is saved by his cast*. Stephen Chbosky got a lot of help from Logan Lerman, Ezra Miller and Emma Watson in the adaptation* of his popular young adult novel “The Perks of Being a Wallflower.”

    The film — like the book — is a smart study of a troubled teen’s first year in high school.

    Chbosky has kept much of his novel’s narrative device — letters written by an unhappy freshman named Charlie (Lerman) to an anonymous* sympathetic* someone.

    Set in a comfortable Pittsburgh suburb in 1991, the film quickly drops us into Charlie’s worried first days, when it seems that in high school he will forever be friendless. He’s intelligent and sensitive. His best friend, Michael, committed suicide* the year before. His second best friend, Susan (Julia Garner), who was Michael’s girlfriend, has joined the “in” crowd, which doesn’t include Charlie.

    His luck begins changing when he braves* a football game alone and bumps into* Patrick (Miller), the strange senior in his shop class*. That brings an introduction to Patrick’s stepsister Sam (Emma Watson).

    From there the film digs into the major theme, which is the messy business of figuring out who you are. There are side issues of sexuality — straight and gay — and friendship. But the engine driving the film is Charlie’s personal history.

    While Charlie is the “wallflower,” more an observer than a partaker* of life, Patrick and Sam throw themselves into every experience. Now they are dragging Charlie along for the ride.

    It starts with a ride. After the first football game, Patrick is racing his pickup* through a tunnel while Sam stands in the truck bed, arms outstretched, screaming for joy. (SD-Agencies)