Plot summary
Charlie assists Don on a serial rapist case by calculating a "hot zone", an area where the rapist is most likely to live. Don is removed from the case after Charlie's formula fails to turn up any leads but later a comment from their father then leads Charlie to change the equation to calculate two points of origin, instead of one, leading to a new suspect. Anthony Heald guest stars. Mathematics used: Geographic profiling, probability theory, 11-dimensional supergravity theory and projectile motion
Credits
Adapted from Wikipedia contributors, Numbers season 1. HTML formatting and reference markers removed.