Peter discovers a lump on Lois’s breast, and the two go to the hospital to have it tested. The test shows the lump to be benign, but Dr. Hartman discovers, by looking in her medical records, that Lois’s mother was a Holocaust survivor, meaning Lois and her children are Jewish. Despite being Catholic, Peter becomes a devout Jew, much to Lois’s chagrin. That night, Peter is visited by the ghost of his father, who warns him that he will go to Hell if he is not Catholic. The next day, Peter decides to convert the family back, and becomes prejudiced against Lois for her Jewish heritage. When Lois’s mother advises not to let Peter suppress her identity, Lois decides to hold Passover, which Peter tries to ruin. Jesus then appears and settles the couple’s disputes. In a minor subplot, Quagmire learns about internet porn and gains large muscles after masturbating to it.