Vincent travels to Cold Spring Harbor Laboratory to speak with David Baltimore, John Coffin, and Harold Varmus about the discovery in 1970 of retroviral reverse transcriptase and its impact on life sciences research.

Vincent, Dickson, Rich, and Alan review the 100 year old finding by Peyton Rous of a transmissible sarcoma of chickens, a discovery that ushered in the era of tumor virology.