Who is Massie Block from Dial L for Loser: A Clique Novel and what is their importance?

Massie Block, Dial L for Loser (Clique Novel), is in the 7th grade and is the leader of a group that has termed themselves The Pretty Committee. When Massie runs away on a co-ed field trip, the others in the committee try to find her and end up getting both Massie and themselves expelled from school.

Massie is a typical rich kid. She lives in a mansion, has a pool, tennis courts, and all of the trappings of the wealthy. She has a crush on a star player for the soccer team at school, whose name is Derrington.

Her true friend is Clair, but Massie treats her indifferently when they are in public. Massie seems outwardly confident but as the novel unfolds it is clear that she is very insecure and lonely.