I showed this movie in Seminary this morning. It is a very touching story of brotherly love. In the early 1800, the churches of the day taught that if you died without being baptized, you would go to hell. This was very upsetting to the Smith family when their oldest child, Alvin, died without being baptized. Their family was relieved to learn that through the restored Gospel of Jesus Christ the priesthood keys would be restored and that Alvin, would indeed be able to go to the Celestial Kingdom. (heaven) See D&C 137.
You can also see the video by clicking here