In Chain of Command, we meet Charlie Boyle, a security guard who has spent two decades at the now-abandoned Brookside Atomic Laboratory. The lab is overgrown and deserted, yet Charlie remains, feeling a sense of duty and familiarity. His life takes an unexpected turn when he encounters George, a mouse who lives in the lab with his family. George's wife, Clara, is anxious about a trap placed outside their door, fearing for the safety of their children. Reluctantly, George approaches Charlie for help, initiating a chain of events that will alter their lives forever.