Homer surprises Marge with tickets for a three-hour getaway at a local health spa. He even arranges for his father to look after Maggie while they are away. But shortly after Homer and Marge leave for their three hours of fun, things begin to go horribly wrong. At Springfield Elementary, Mrs. Krabappel notices Bart has head lice. Principal Skinner suspects Lisa is a neglected child after a playground beating leaves her dazed and shoeless. And when child welfare workers visit the Simpson home, they find Maggie drinking from a dog bowl as Grampa sleeps nearby. When Homer and Marge arrive home, the welfare workers inform them the children are being relocated to a foster home: The Flanders’ residence.

Horrified at the thought of letting the Flanders raise their children, Marge and Homer plead their case in court. The judge concludes the couple has a lot to learn about parenting, and orders them to complete a Family Skills course. Meanwhile, Bart and Lisa cope with life at the Flanders’ home, where eating non-fat ice milk and bible trivia are considered fun. But they grow increasingly concerned about Maggie, who exhibits signs she may be accepting Ned and Maude as her real parents. Terribly homesick, the children smuggle a note to their parents, telling them how much they are missed.

During a game of bible trivia, Ned and Maude realize that Bart, Lisa and Maggie were never baptised. In a panic, Ned rushes the children to the Springfield River intending to perform his own emergency baptism. Homer learns of the scheme and, realizing his children are moments from becoming official members of the Flanders’ clan, rushes to the riverbank. As Ned begins to pour the baptismal water, Homer jumps in front of his son, taking the brunt of the liquid. Maggie, meanwhile, looking confused, looks back and forth between the two families. Realizing who she loves most, she embraces her true family.