This reading seems to be mostly about the bloodlines of the kings and their women. Many times the birth stories of Vyasa and his mother were repeated in order to show different ways the story is told. Vyasa's mother was born a twin from the mouth of a fish and adopted by a fisherman. This woman had Vyasa with the Brahmin Parashara who promised she would become a virgin again and she would smell sweet instead of fishy.
This led to the eventuality that a king came along and wanted her so in order to have her the king's son gave up any claims to the throne and vowed to never marry or have children. Thus Bhishma became the overseer of Satyavati's children, who all died. At which point she called out to Vyasa to take up the widows of her other sons, and then his sons became heirs to the throne instead.
Then from there one of Vyasa's sons married a woman named Kunti who birthed a son by the sun and put him in the Ganga to float away where he would end up being picked up by a woman in Anga.
It's all a whirlwind of intermixed bloodlines and a terrible fate for Bhishma, born as Devavrata!
