Yoni Roshko (Yoav Rotman) is a boy living in a small seaside moshav. Desperate to grow up, he does his classmates' homework so he can spend their money on a bodybuilding powder, stretches with weights tied to his legs, and screams into the wind to thicken his voice. He struggles to memorize his portion of The Torah on time for his upcoming Bar Mitzvah. His small size makes him an easy target for bullies, and his distant, irresponsible parents, Miri (Ronit Elkabetz) and Gidi (Tzahi Grad), are no help. Then the institution that housed his 17-year-old autistic brother Tomer (Michael Moshonov) is shut down, and Tomer is sent to live with his family until a new place can be found.
Mabul contains examples of:
- Bathroom Stall Graffiti: The bathroom walls at Yoni's school are absolutely covered in graffiti.
- Bug Catching: Tomer is obsessed with bugs. Miri buys him containers so he can store them. Some of them escape one night, and when Yoni wakes up, he's horrified to find his mattress infested with bugs.
- If It Tastes Bad, It Must Be Good for You: Yoni grimaces as he drinks his bodybuilding shakes.
- Interrupted Intimacy: Miri is about to have sex with Doron when she receives a call telling her that Tomer's institution has shut down.
- It's All About Me: Gidi doesn't seem to care very much about how his screw-ups affect other people. When he accidentally cancels the catering for Yoni's Bar Mitzvah, he tells him, "I've had a difficult week. You don't understand." Later he says, "I apologized! What more do you want?"
- Only Known by Their Nickname: Yoni and Miri's full first names are Yonatan and Miriam, but neither name is used except at the Bar Mitzvah.
- Potty Failure: During his first night at home, Tomer goes into Yoni's closet and stands there all night. By the next morning, he's wet his pants.
- The Stoner: Gidi secretly grows marijuana at his workplace and spends a lot of time stoned.
- Teens Are Monsters: The bullies not only smash a window and threaten to beat Yoni up but also send Tomer out to sea alone in a rowboat, almost killing him.
- Your Mom: Bullies taunt Yoni about his mother's affair with Doron.