The show focuses equally on the relationships between Don Eppes, his brother Charlie Eppes, and their father, Alan Eppes (Judd Hirsch), and on the brothers' efforts to fight crime, normally in Los Angeles. A typical episode begins with a crime, which is subsequently investigated by a team of FBI agents led by Don and mathematically described by Charlie, with the help of Larry Fleinhardt (Peter MacNico) and/or Amita Ramanujan (Navi Rawat). The insights provided by Charlie's mathematics are always in some way crucial to solving the crime.