Akin to 1994's "Heavenly Creatures" without the murder and fantasy sequences -- and with a twist of distrust hanging in the air -- "My Summer of Love" is a squirmy parable about two 17-year-old girls from opposite ends of the social spectrum who find in each other's company a powerful but uneasy release from their individual angst.

Mona (Natalie Press) is a plain and provincial redhead with an artistic bent, sexually gullible and unsure of herself. She's been miserable since her caretaker older brother (the superb Paddy Considine) returned from prison, adamantly (read: desperately) clinging to newfound born-again Christianity.

Tamsin (Emily Blunt) is a brazen, sultry hothouse brunette booted from a series of private schools ("Apparently I'm a bad influence") and seemingly haunted by the death of her anorexic sister while staying the summer at her neglectful daddy's manse in the hills above Mona's depressed Yorkshire factory town.

When they meet, this pair with nothing in common discovers an addicting synergy between them that escalates into obsession that knows few boundaries, be they psychological or even sexual. "If you leave me, I'll kill you," they swear to each other as if it were the most loving promise in the world.

Under the unadorned but intensely atmospheric direction of Pawel Pawlikowski (whose similarly visceral "Last Resort" was released in 2001), the inexperienced young actresses give such unaffected performances that the film develops a voyeuristic quality as the girls' relationship takes on the momentum of a runaway train.

But the film, adapted from a novel by Helen Cross, derails with an ending that is open-ended in a way that fails to offer even an allusion to the future for the audience to contemplate. All that "My Summer of Love" needed to finish as stirringly as it proceeded through its previous 80-odd minutes was a hint as the screen fades to black -- something as minimal as the direction a character is walking on a road in the last scene. As is, however, the aftertaste of dissatisfaction threatens to overwhelm the sensations the film inspired in the first place.