The committee project goes about as badly as you can imagine, and it turns out that Norman is slow, Philip is lazy, and Laura is a good worker but Margaret just doesn't like her (and we know Nancy has at least a little something to do with that).
It all comes to a head one day toward the end of the project when Laura and Margaret are staying late to use the encyclopedias. (Pro tip: Don't take the Internet for granted.)
Margaret finds out that Laura is Catholic, which gets her to thinking. In fact, she's thinking so hard that she ends up copying directly from the World Book—which is a big no-no.
Laura calls her on it, and Margaret gets defensive. Then Margaret accuses Laura of going behind the A&P with Moose Freed. Laura is very upset, and demands to know just where Margaret is getting her information.
Margaret starts to second-guess herself a little bit since her source is Nancy and she knows Nancy has lied to her before.
Laura storms off in tears, and Margaret runs after her, doing the best she can to apologize.
Laura doesn't exactly accept the apology, and Margaret ends up following her to Confession.
This is Margaret's first experience in a Catholic church, and she goes inside the confessional. It doesn't go that well though, and Margaret winds up feeling scared and sick.
Once she gets home, Margaret gets back in touch with God, and does her own confession of sorts: "Just because I felt mean I took it all out on her" (19.57), she says.