Since camp is usually something a knowing audience imposes on a movie, rather than the other way around, self-conscious attempts at camp are usually doomed to fail, as evidenced by Troma's catalog, in which the fun stops at the titles (The Toxic Avenger, Surf Nazis Must Die!). The few exceptions, including many works of Russ Meyer and John Waters, succeed because they're not just recycling camp, but filtering it through their own unique sensibilities. Psycho Beach Party, a vigorous and lighthearted adaptation of Charles Busch's 1987 off-Broadway play, confuses the problem even further by being a parody of camp, a concept that would seem ridiculously postmodern if that term still had any meaning. Cross-pollinating sun-and-surf trifles like the Gidget and Avalon/Funicello comedies with '50s television, '80s slasher films, and four decades of Z-grade trash, it spends too much time winking at its audience to succeed beyond a handful of clever references. But, uneven as it is, Psycho Beach Party is salvaged by a game cast and an unfailingly pleasant tone, a refreshing antidote to the smugness peddled by Troma and other cynical enterprises. As a naïve, perky tomboy with no interest in sexa role Busch himself originally played in dragthe delightful Lauren Ambrose (Can't Hardly Wait) reacts as Gidget would if she'd discovered all the depravity behind her squeaky-clean world. After a trip to the beach introduces her to the surfing crowd, a series of bizarre slayings threatens to spoil the summer, with suspects ranging from a rhyming surf guru (Thomas Gibson) to a washed-up B-movie queen (Kimberley Davies) to a Swedish exchange student (Matt Keeslar). But the prime suspect may be Ambrose herself, who is given to psychotic spells in which she morphs into a vengeful sex goddess or a trash-talking Safeway cashier. In bringing Busch's play to the screen, director Robert Lee King clearly had a lot of fun meticulously recreating the look of cheap beach movies, using stock footage and rear projection for the surf sequences and filling out the set with Tiki dolls, gaudy wooden shacks, and squarish swimwear. But for all its sharp detail, spirited performances, and obvious affection for camp, Psycho Beach Party is still a parody of a parody, which explains why it's hysterical without ever being all that funny.