Arcee is part of a faction of a robotic alien race called the Autobots, who fight for freedom against the evil Decepticons. Despite being the smallest member of the team, she is considered the most reliable soldier by her leader Optimus Prime. Her force of personality and tough as nails attitude fit perfectly with her skills in melee combat. But these traits hide a vulnerable side of Arcee. She has lost two partners, who were killed by the Decepticons and those losses shook her to her very core. While she is extremely loyal to her leader, Arcee will sometimes bend the rules and often lets her feelings of revenge get the better of her. When she was initially assigned as guardian of the human teenager Jack, she was less than thrilled, but over time she has grown close to him and is not only his friend but often acts as a mother-figure. The loss of her partners makes her very overprotective of Jack.