Fred, also known as The Great Key-Keeper, is the janitor of Jefferson County Middle School. He's regarded as a somewhat mythical figure by the students.
Fred is regarded as a mysterious, and somewhat mythical figure by the students of the middle school. He is rarely seen, even by fellow staff, and it is widely believed that he leaves secret signs to send students on "quests", which seem set to help them with their problems.
When he appeared before Milo and Melissa after their quest, they thanked him for helping them. He spoke in a very soft tone, and 'bestowed' upon them some cleaning supplies before requesting they clean up the hallway.
Fred has olive toned skin and dark eyes. His short black hair is streaked with gray and slicked back, and he has a black mustache and a large goatee. He wears an olive green shirt with symmetrical pockets on the chest, rolled up sleeves, and a downturned collar. His pants are dark with visible seams, and he wears a pair of red sneakers with white soles and laces.
In The Math Book, Milo, Melissa, and Zack embark on a quest, continuously finding signs left by the janitor on the way. At the end of their adventure, Fred approached them, requesting they help clean up before suddenly vanishing again, unfortunately before Zack could see him. He returned momentarily, however, to pick up his caution sign.