Massie Block is the true Alpha of Westchester, with perfect brunette hair and beautiful amber eyes. She is the epitome of perfect, despite her insecurities with boys at times. She is the most popular in her group. She is rich and gets basically everything she wants. Massie has a horse named Brownie and a female pug named Bean, as well as memberships to exclusive clubs and several credit cards. She is also known for constantly making an IN-OUT list on her PalmPilot, called ¨Current State of the Union¨, based on the events she experiences. Nevertheless, in the New York Times Book Review, Laura Bourdon wrote, "Puh-lease, as Massie Block would say in reference to these insults directed at her so-called extravagant lifestyle." All the same, she is the official ruler of Octavian Country Day until Claire, a new girl from Orlando, comes and seemingly ruins it all. Massie hates Claire in the beginning, because of the way she dresses, she's poor, and she wants nothing to do with her. But then Massie realizes Claire can actually be cool and they become friends. She calls Claire KUH-laire. This is suppose to be an insult, but when they become friends, it is more of an endearing term. Massie is a little spoiled, but loves her friends, and will always stay true to them, unless of course they backstab her.
In the first book, Massie falls for high-schooler Chris Abeley, but discovers that he has a disgustingly beautiful girlfriend named Fawn. In the second book, Massie and Claire throw a Halloween party and they both fall for a Briarwood boy named Cam Fisher. Yet through tough times, Massie and Claire begin to rely on each other. In the third book, Massie finds out that Alicia has started her own Clique and discovers Cam likes Claire, not her. While dealing with Alicia, Massie begins crushing on Derrick Harrington (Derrington). Her life is nowhere near perfect, with Nina the Spanish boy charmer (Alicia Rivera's gorgeous cousin from Spain), getting expelled from OCD in Lake Placid, losing the lead role in "Dial L for Loser" to Claire, searching for the key to a secret room, and not finding it first, getting Chris to like Skye Hamilton even though they were falling for each other, and designing the overflow trailers. However, throughout the series, Massie is known as being the most under control, over-thinking, and overall coolest member of the Pretty Committee, making her the true Alpha of the Clique. But not only is she the Alpha of the Clique, but, seemingly, the whole Westchester. Throughout the many stories, Massie uses her quick wit to insult anyone she wants. Her lip gloss flavor that comes with the Summer Collection is "Mango- magawd". Her IM screen name is Massiekur.