This episode of the "Science Nation" series, titled "Indian Hand Talk," explores the unique Plains Indian sign language, also known as hand talk. Documentary footage from 1930 captures this universal language used by both deaf and hearing Native Americans for over 200 years. University of Tennessee linguistics professor Jeffrey Davis, supported by the National Science Foundation, is documenting the grammar, structure, and applications of this rare language. Despite its richness and neutrality among diverse tribes, only a few users remain today. The video emphasizes the cultural importance of preserving this disappearing language and the ongoing efforts to compile a dictionary. With its focus on hand talk's role in inter-tribal communication, this content is crucial for understanding historical linguistics, cultural anthropology, and indigenous studies.