S2·E4 Nun But the Brave

Guilt is in the air in Brooklyn: Katie prays to be spared from her history exam, then is devastated when her teacher, the tough Sister Rafael, dies--guilty to the point where she blames Alan and eventually vows to become a nun. In the meantime, both Grandma and Nathaniel make the Silvers feel guilty about shopping at Fairmart, the supermarket that gives trading stamps, rather than at the neighborhood grocery.