A prison transport bus crashes after maneuvers by two other vehicles, several inmates escape, including the dangerous McDowd. Charlie gets on well with CHP Officer Morris on the scene and works out mathematically it was no accident, both other drivers probably were in the game. Dad is worried Don might be returning to the period he regularly worked in fugitive retrieval, especially now a former colleague, burly federal marshal Cooper, is on the same case. After finding a lesser fugitive, Charlie's mathematical probabilities approach helps reconstructing the remarkable movements of McDowd in LA, which leads to a worrisome motive relating to a DEA case and likely further accomplices...