Donovan is an ordinary middle school student with a habit of getting into trouble. Despite lacking the conventional academic brilliance of his peers at the Academy for Scholastic Distinction, he is an essential member of the robotics team, driving their machine, Heavy Metal. He is resourceful, impulsive, and fiercely protective of his friends and family. When a runaway truck threatens a neighborhood house, Donovan instinctively acts to prevent a disaster, setting off a chain of unexpected consequences.

Noah is a student with an IQ over 200 who transfers to Hardcastle Middle School to escape the predictability of the Academy for Scholastic Distinction. He deliberately seeks out average experiences, celebrating mediocre grades and enthusiastically signing up for cheerleading despite his complete lack of athletic coordination. His highly literal thinking makes social interactions difficult for him to understand, often leading him to misinterpret situations.

Megan is the dedicated head cheerleader at Hardcastle Middle School, a position she has held since the sixth grade. She carefully choreographs routines, writes cheers, and anchors the human pyramid. Her mandatory positive attitude is severely tested when Noah joins her squad, as she views his lack of skill as a direct threat to her team's reputation. She is deeply affected when a runaway truck nearly destroys her family's home.

Hash Taggart, nicknamed Hashtag, is the captain of the lacrosse team, quarterback of the football team, and a highly popular student. He is deeply invested in his athletic status and the winning streak of his teams. He initially views Noah's cheerleading as an embarrassment and attempts to force him off the squad to protect the lacrosse team's image.

Brad is a munitions specialist and tank commander who runs his household with military precision. He sets rigid expectations for those around him and expects his baby daughter to adhere to a strict schedule. His gruff demeanor creates friction at home, particularly with Donovan, though he harbors a more vulnerable side regarding his parenting abilities.

Katie is Donovan's older sister and a former cheerleader. She lives in a crowded household with her husband, her new baby, and her brother. She balances the chaotic dynamics between her strict husband and her impulsive sibling, often stepping in to help others.

Chloe is a student at the Academy and a dedicated member of the robotics team. She is responsible for maintaining the hydraulic system of the robot Heavy Metal. She is observant and possesses strong common sense, often picking up on details that elude her highly academic peers.

Daniel is one of Donovan's friends at Hardcastle Middle School. He finds Donovan's unpredictable behavior highly entertaining but prefers to watch the resulting chaos from a safe distance. He is opportunistic and quick to capitalize on leverage when he discovers secrets.

Daniel Nussbaum is another student at Hardcastle Middle School who frequently hangs out with Donovan. Like his friend Daniel Sanderson, he is quick to distance himself from unpopular students and looks for ways to use situations to his own academic advantage.

Beatrice is a dog originally belonging to Brad, but she grew deeply attached to Donovan during Brad's military deployments. She sleeps in Donovan's room and acts instinctively to defend him from any perceived threats.

Kandahar, nicknamed Kandy, is Beatrice's energetic and unruly puppy. He is difficult to train and frequently causes disruptions around the house, relying on Donovan as a source of comfort.

Russ Trussman is a local television reporter with conspicuously perfect features. He investigates local news stories with a skeptical eye and searches for inconsistencies in public narratives, refusing to accept events at face value.

Mr. Osbourne, known as Oz, is the robotics teacher at the Academy. He coordinates the students as they build and program Heavy Metal, preparing them for an upcoming demonstration.

Abigail is an intelligent student at the Academy who handles the coding and operating system for the robotics team. She is highly focused on academic performance and becomes intensely frustrated when technology fails.

Tina is the infant daughter of Brad and Katie. Her unpredictable sleeping and crying patterns constantly frustrate her father's attempts to put her on a strict schedule.

Mrs. Torres is the cheerleading coach at Hardcastle Middle School. She appreciates school spirit over athletic skill and insists that anyone enthusiastic enough should be allowed on the squad.

Donovan's mother manages a crowded, chaotic household. She often jumps to the conclusion that Donovan is responsible whenever something goes wrong in the house.

Donovan's father lives in the bustling Curtis household and frequently reacts with surprise to the dramatic events surrounding his son.

Mr. Taggart is Hash Taggart's father. He is highly protective of his son and quick to threaten official action when he believes his family has been wronged.

Mr. Mercury is Megan's father. He experiences a terrifying incident at his home and expresses deep gratitude toward the individual who averts the disaster.

Peter is Megan's younger brother. He opportunistically capitalizes on an emergency at his home by selling photographs of the scene to the local news.

Marie Curie is Chloe Garfinkle's well-behaved dog and Kandahar's littermate. Her obedience highlights Kandahar's lack of discipline by comparison.

The careless driver of a tanker truck whose failure to properly park his vehicle sets off a dangerous chain of events in a residential neighborhood.

Coach Franco manages the lacrosse team at Hardcastle Middle School. He maintains strict disciplinary standards for his athletes, ensuring they behave appropriately outside of practice.