In Alex Blake's (Jeanne Tripplehorn) first case with the BAU, the team travels to Texas after an ambulance carrying a prisoner overturned on a deserted highway. The prisoner - an UnSub known as 'The Silencer' - escaped after sewing the guard's mouth shut and killing him. Despite the UnSub having been in the prison system, his identity is unknown. He was admitted as a John Doe after being convicted on an illegal firearms charge. When a note is found inside the guard's mouth -and further messages appear in the mouths of other victims in the area - the team works to build the profile of a man whose lifelong search for silence continues to elude him.