Ben is a 12-year-old student at the CIA's Academy of Espionage who excels at math and code-breaking but struggles with physical combat. After surviving his first semester and foiling an enemy plot, he hopes for a normal summer but instead receives a death threat from the evil organization SPYDER. He frequently doubts his own abilities compared to his elite classmates but possesses strong problem-solving instincts.

Erica is a 15-year-old legacy student at the academy, known by her peers as the "Ice Queen." As the descendant of highly accomplished CIA agents, she has trained for espionage her entire life and is exceptionally competent in combat, surveillance, and strategy. She harbors intense resentment toward her father for damaging her future career prospects.

Alexander is a renowned CIA spy and Erica's father, famous for his daring adventures. In reality, he is heavily reliant on his unearned reputation and often takes credit for others' work, masking a deep insecurity and a desperate need for his own father's approval.

Murray is a former spy school student who was previously exposed as a mole for the evil organization SPYDER. Though he is officially serving a sentence in a high-security detention facility, he inexplicably approaches Ben in public to deliver a threatening recruitment offer.

Cyrus is Erica's grandfather and Alexander's father. Operating under the code name Agent Klondike, he is a legendary, highly competent senior spy who comes out of retirement when his family faces danger. He is exceptionally skilled but intensely critical of his son's failures.

Joshua is a former student at the CIA's Academy of Espionage. Known for his exceptional skills, his time at the academy abruptly ended after a devastating explosion in his dorm room. His legacy casts a long shadow over the current students, particularly those who were closest to him.

Woodchuck is the eccentric and intense administrator of the Happy Trails spy camp. Dressed in handmade animal skins and armed with throwing knives, he takes wilderness survival very seriously. He is tasked with protecting Ben and teaching him how to survive off the grid in the deep forest.

Mike is Ben's best friend from his normal, non-spy life. He believes the CIA's elaborate cover story regarding Ben's school, having been bribed with college tuition and a car to keep quiet. He serves as Ben's main connection to ordinary teenage life.

Zoe is a fellow student at the spy academy who considers Ben a friend. She gave him the nickname "Smokescreen" because she stubbornly believes his outward clumsiness is an elaborate cover for lethal espionage skills. She is perceptive and quick to question authority when danger arises.

Warren is a spy school student who holds a deep, unrequited crush on Zoe. Because Zoe pays attention to Ben, Warren views Ben as a rival and takes joy in Ben's misfortunes, such as mocking his poor bunk assignment in the cabin.

Chip is a spy school student who initially clashed with Ben but has since become a reliable friend. He is Hank's younger brother and actively tries to undermine him, frequently suggesting pranks to get back at his older sibling for years of mistreatment.

Hank is a resident advisor at the academy and a counselor at the summer spy camp. Intensely competitive and prone to grudges, he immediately threatens Ben with harsh physical punishments to ensure their cabin wins the camp's Color Wars. He harbors deep resentment toward his younger brother.

Claire is a tough, highly trained exchange student from the British intelligence agency MI6. She is dismissive of the American students, frequently calling them weak, and constantly challenges their survival strategies during camp exercises.

Jawa is a fellow student at the spy camp and one of Ben's cabinmates. He is highly motivated to win the camp's Color Wars and acts as a dedicated team player, frequently joining Ben in mandatory physical conditioning exercises without complaint.

Agent Hamilton is an undercover CIA operative assigned to protect Ben during his brief visit home. Nicknamed "Soccer Mom" by Ben due to her suburban disguise, she is highly skeptical of Ben's observations and fails to take his security concerns seriously.

Tina is Ben's former resident advisor at the spy academy. Having recently graduated, she is deeply frustrated by her assignment to a safe city, feeling she is missing out on the exciting fieldwork Ben experiences.

Brandi is an employee at the Apple Valley Reformation Camp for Delinquent Teens. She oversees the inmates and firmly believes in the facility's relaxed, contemplative approach to juvenile rehabilitation, remaining completely oblivious to the deception occurring in her high-security wing.

Lousy Sideburns is a dedicated Civil War reenactor participating in a mock battle near a remote farmhouse. Unaware of the real espionage operation taking place, he takes his role as a cannoneer extremely seriously until Ben commandeers his station.