Smith, an 18-year-old film student who identifies sexually as "undeclared", has been having strange dreams recently. He is going to college with his best friend, Stella, whom he has known since junior high, and finds a note saying he is the "chosen son." He has a roommate named Thor, whom he lusts after even though Thor is straight. Smith and Stella go to a party where Stella hooks up with a girl named Lorelei, who Smith recognizes from one of his dreams. Later, a red-haired girl vomits on his shoe, and Smith also recognizes her from a dream. Smith eventually gets picked up by London, a British student. They have sex, but to Smith's chagrin, she does not want to be with him except during sex.
Smith visits a nude beach and meets a man named Hunter. They start having sex, but Smith is disappointed to hear Hunter is married. Stella discovers Lorelei is not only unstable, but a witch with psychic problems caused by rejection. Stella keeps trying to dump her but has difficulty as Lorelei begins trying to kill her. Smith walks in on Thor and Thor's best friend, Rex, wrestling in their underwear. London seduces Rex, convincing him to have a three-way with her and Smith for Smith's 19th birthday.
During this time, Smith continues dreaming of the red-haired girl. In his dreams, they are both pursued by people wearing animal masks. Smith finds out that a girl was killed and her head cut off. He later meets Madeline, who appears to be the same red-haired girl. She tells him that she had a twin sister named Rebecca who was kidnapped many years ago by men wearing animal masks. Stella is attacked by Lorelei in a bathroom, but saves herself by spraying water on her, causing Lorelei to burn up.
The animal-masked people finally capture Smith, London, and Smith's mom. They are bundled into a van to be driven to meet the head of a secret cult. Smith learns that the cult leader is his father, although he was always told that his father died when Smith was young. The three also learn London is another child of the cult leader, making her and Smith half-siblings.
Stella, Oliver, and the perpetually stoned "Messiah" pursue the van. Oliver has powers like Lorelei's but uses them for good. It turns out that Oliver meeting Smith (and flirting with him) was not chance; he was trying to protect Smith from the cult. The Messiah was only acting stoned as a cover and also wishes to protect Smith. The animal-masked people turn out to be Thor, Rex, and Hunter, whose mission is to get London and Smith to a secret underground shelter to survive the explosion of dozens of nuclear bombs. Non-cult members will be annihilated, and the cult will take over the world with Smith as its leader.
The Messiah tries running the van off the road, and both vehicles accelerate towards a bridge that is out. Smith's father presses a button and the Earth explodes.
The film received mixed reviews from critics. On the review aggregator website Rotten Tomatoes, 59% of 105 critics' reviews are positive, with an average rating of 5.8/10. The website's consensus reads: "Jumbled and shallow yet easy to watch, Kaboom is a one-night stand that isn't meant to lead anywhere – but is fun enough while it lasts."[11] On Metacritic, the film has a 64/100 rating from 24 reviews, indicating "generally favorable reviews".[12]
Bruce DeMara of the Toronto Star praised the film's cast and called it "Araki's most ambitious [film] to date, with a quick pace, music that's hip and cool and a mood that alternates between playful and eccentric."[13] Sam Adams of Philadelphia City Paper was much more critical about it, and said it was "less a movie than a masturbatory doodle, a sloppy, shoddy regurgitation of Araki's pet trope that tries to pass off its slipshod structure as a free-wheeling lark."[14]
