Katherine gets a homemade dress as a present from Webster: an unflattering lime green one that says "I Love Paris" and has a large, battery-powered, lighted Eiffel Tower embedded on it. She can't admit to Webster that she doesn't like the dress, and he wants her to wear it for a special occasion. Cassie tells her to wear it as she goes out the door and then change at the neighbors' house while Webster isn't looking. The day she chooses to wear the dress is the day she participates in an experiment where she and other students will be observing four children's interaction with toys - those four children are Webster and three of his classmates.
—Attmay