A tone of somber seriousness hangs over Lea Pool’s English-language directorial debut, a well-intentioned but curiously out-of-date tale of a friendship between two girls at a posh prep school that turns sexual and then tragic (but still, of course, uplifting in an odd way). “Lost and Delirious” is certainly earnest–indeed, far too earnest for its own good; but though it’s more explicit than novels or films on similar subjects used to be, it’s really not much more insightful or compelling than John Knowles’ once widely-praised, vaguely homoerotic “A Separate Peace” (made into a very bad film by Larry Peerce back in 1972).

Based on Susan Swan’s novel “The Wives of Bath,” Judith Thompson’s screenplay is told mostly from the perspective of Mary (Mischa Barton), a quiet, unhappy girl whose mother’s recently died and whose remarried father enrolls her at Perkin Girl’s College. She becomes the roommate of old-timers Pauline (Piper Perabo) and Victoria (Jessica Pare). The former is a brilliant but unstable sort, a kind of brainier version of the disheveled character Ally Sheady played in “The Breakfast Club,” and also a good fencer; the latter is rangier and more coquettish, reminiscent of a young Nancy Allen. Mary comes to realize that the two are engaged in proto- lesbian experimentation, but when Victoria’s younger sister finds them in bed together, Victoria denies the relationship, drops Pauline, and ostentatiously gets together with a guy from a nearby school. Pauline, a troubled adopted kid who’s on the edge under the best of circumstances, goes bonkers trying to win Victoria back, publicly announcing her love in the most embarrassing ways and even resorting to violence (at one point she challenges the boy to a duel, and wounds him). When Victoria persists in resisting her advances, neither Mary nor the school’s teachers can control Pauline’s increasing hysteria. There’s an over-the-top ending involving a bird (a falcon?) which Pauline has secretly nursed back to health after it had broken a wing and which she’s made a pet.

The first half of “Lost and Delirious” is a bit familiar, but generally sound. The characters are reasonably well-drawn, even if the two instructors, Miss Vaughn (Jackie Burroughs) and Miss Bannet (Mimi Kuzyk), seem like something out of Lillian Hellman’s “The Children’s Hour,” and the good-natured gardener with whom Mary develops a friendship (Graham Greene) is far too obviously intended as the local down-to-earth sage. (The advice he offers, however, is so obscure that he comes across as sphinx-like). More importantly, though, the relationship between Pauline and Victoria is portrayed intelligently and with admirable discretion. Unfortunately, when the plot (and Victoria) turn, the picture becomes unalloyed melodrama. Pauline’s efforts to get Victoria’s attention grow increasingly overwrought, and by the last twenty minutes she seems nearly psychotic (indeed, one would have to charge the administrators with malfeasance for not getting her serious psychiatric help). And the entire metaphoric subplot about the injured bird is one of those devices that might work on the printed page, but when translated into cinematic comes across as ridiculously heavy-handed. (It reminds one of that old Andy Griffith episode titled “Opie the Birdman.”)

Of the actors, Perabo is certainly impressive in a flashy role; she’s seizes every opportunity to emote, though by the end she’s overdoing it. Pare and Barton are okay, but they’re completely overshadowed, and Greene looks amiably lost. Nobody else makes much of an impression.

Actually, a story very much like this one–though involving guys rather than girls–was told considerably better in 1999 in “Get Real.” That picture had the virtue of treating things with a bit of humor that made its last third less bombastic than here. “Lost and Delirious” isn’t terrible, but with a lighter touch and greater subtlety, it could have been far better than it is. And whatever you do, don’t watch it in tandem with Richard Linklater’s 1993 “Dazed and Confused.” That titular combination would be just too much.