Edgar is the main character of all 3 Atherton books. He is thin and wiry, and loves to climb. He is the first and last person to both climb down to the flatlands and up to the highlands. He has also climbed down below Atherton from to outside to reach the docking station..

In Atherton: The House of Power, Edgar is introduced as being raised in the Grove on tabletop. He enjoys playing around, and is often yelled at by Mr. Rattikan. A girl named Isabel often follows him around, although he regards her with annoyance. He has dim memories of his father, and a book that his father told him to find. One day, he climbs higher than ever before, and discovers the book. However, he cannot read, and climbs to the highlands to find someone to read it to him. There, he meets Samuel, who translates for him and begins teaching Edgar how to read. The book tells that one day, the 2 inner levels of Atherton will sink below the flatlands. While on the highlands, Edgar is chased by Sir Emerik, who desires to overthrow Lord Phineus and take power for himself. Edgar escapes by lighting Sir Emerik's hair on fire. Edgar climbs down to tabletop and then to the flatlands. However, on his way down to the flatlands, he falls once, resulting in the loss of a pinkie finger, which was caught on the cliffs. At the bottom, he is surrounded by monsters called Cleaners, which eat the trash thrown off of Tabletop. Edgar is rescued by two mysterious men, named Dr. Kincaid and Vincent. They teach him how to kill and eat cleaners, as well as some of the history of Atherton. At the end of book one, Edgar goes back to the cliffs of tabletop, only to discover that they have disappeared, and that the flatlands and tabletop are now level.

In Atherton: Rivers of Fire, Edgar returns to Tabletop and tells them to prepare against the assault from the Cleaners and those living in the Highlands. Edgar and his friends are captured by Erik and Lord Phineus. The group goes into a cave in the house of power, which leads to the source of water for all of Atherton. There, Samuel finds his father. After going into a lab, Edgar witnesses the reawakening of Dr. Harding. However, Edgar is kidnapped by Erik, and dragged back to the house of Power. Dr. Harding follows them, and frees Edgar, killing Sir Emerik in the process. Dr. Harding lets Edgar rest, but with the rising water levels brings out an emergency boat prepared long ago. The boat only has room for one, and Dr. Harding says goodbye before putting Edgar on the boat and pushing him out of the flooding room. At the end of the book Edgar sits on the edge of Atherton and thinks about all that has occurred.