The Perks of Being a Wallflower, Stephen Chbosky, 103mins (12A)

Starring: Logan Lerman, Emma Watson

This surely couldn't be wetter or weedier than its promotional poster – could it?

Stephen Chbosky has adapted and directed his bestselling novel about a sensitive, withdrawn teen starting at high school in suburban Pittsburgh.

Logan Lerman plays Charlie, the title wallflower who blooms under the wing of two seniors, Sam (Emma Watson) and her flamboyant gay stepbrother Patrick (Ezra Miller). Rites of passage soon follow, though it's soft-end stuff like hash brownies and Rocky Horror Show rather than anything that might actually interest us.

Compare it to the strange, mesmerising The Myth of the American Sleepover, and it looks hopelessly synthetic and derivative. (The year is supposed to be 1991, but you'd never know it.) All eyes will be on Emma Watson, shrugging off Potter but hardly convincing as the free-spirited kook.

"Let's go be psychos together," she says, looking the least likely psycho ever. Chbosky wants to capture that Cameron Crowe mood of wistful, music- loving youth and their mixtapes (remember them?), but it comes out too arch, too mannered – everyone talks as though they mean to be overheard. And the fuss it makes over the mystery song that Sam once heard on a car-ride and has searched for ever since is really not a mystery at all – it's "Heroes" by David Bowie, widely available since 1977.