When Bart scams the town out of wedding presents he is finally sent to a juvenile detention center. While he is tethered to Gina, a female inmate (who is also his juvie nemesis), she escapes and the two of them go on the lam a la "The Defiant Ones".
During their time together, they discover they have much in common and when they are caught Gina admits that it was all her doing. Bart is exonerated for his crimes and set free.
In the end, Gina reveals that she has no family, so Bart takes it upon himself to set up a Simpsons family dinner inside the prison just for Gina.