There are two introductions.
In this eight-part series of Dzogchen teachings, Geshe Tenzin Wangyal Rinpoche explains the core tenets of Dawa Gyaltsen, a meditation master of the eighth-century Bön Buddhist tradition of Tibet. These teachings are meant to lead one to a clear and blissful experience of what the true nature of the mind is.
This video also contains subtitles in English