Adam-12 is a television police drama that followed two police officers of the Los Angeles Police Department, Pete Malloy and Jim Reed, as they patrolled the streets of Los Angeles in their patrol unit, 1-Adam-12.

U.S. Marshal "High Pockets" Henderson discovers the body of Bud Blythe near the town of Farewell. After leaving his fingerprints on a photograph of Blythe's sister Joy, who traveled West with Blythe to start a ranch, High Pockets informs the sheriff.

After his assistant, Bud Lester, is killed, Texas Ranger Speedy Meade bids farewell to his girl friend, convent student Mary Dillman, and sets out to break up a gang of cattle thieves operating on the border.

The Earl of Dunhaven, who disinherited his son for marrying an American, tries, on his deathbed, to leave his estate to his nephew, the Honorable Guy Wyndham. To stop him, the Dunhaven solicitor, John Grahame, travels to America and finds the earl's grandson, Jim Dunn, a Wyoming cowpuncher.