This dire nocturne from writer-director Carter Smith explores a love triangle between the ghost of a bullied teenager (Noah Silver), the girl (Morgan Saylor) who discovered his corpse, and that other boy (Cameron Monaghan) who just came over to see her rock collection but couldn’t help noticing their risen classmate standing outside, looking all damp and vulnerable in his skivvies and portentously cracked Harry Potter glasses, wanting an exchange of whispered sweet nothings. Good old adolescence: Everything’s weird, nothing makes a single lick of logical sense, and all the feelings are just so very intense. This is how you turn Christopher Barzak’s young-adult novel One for Sorrow into a Sundance-approved motion picture. First, recruit sensitive and eager young actors into thinly but artfully sketched roles. (Liv Tyler also appears, as a variously incapacitated mom.) Next, try to distract the audience from possibly laughable dialogue with the requisite wan blue cinematography and soundtrack clumps of minor piano chords. Finally, remember, and never doubt, that sexual trepidation sometimes can be downright ghoulish. Smith patiently indulges the occasional full-blown horror-movie freakout, but it seems like he’d rather dwell in his film’s rather touching insistence on the solemn dignity of teen angst.