The Tale Of Svipdag!

Now all is clear to us. See here. In section II, a yeoman's son hight Svipdag, seeking service with the Swedish King Adhils, kills four of Adhils' berserkers in single combat (holmgang) and a fifth when the remaining eight ambush him later. Adhils banishes the surviving seven and makes Svipdag, who is favored by Queen Yrsa, his sole bodyguard. Clearly there will be more to be told about Svipdag.

Meanwhile, however, section III at last begins the story of the Danish King Hrolf who rules from the age of sixteen. Everything that has gone before has led to this:

Frodhi ruled but was overthrown by Hroar and Helgi;
Helgi raped Olof who bore Yrsa;
Helgi married Yrsa who bore Hrolf;
Olof told Yrsa of her parentage;
Yrsa married Adhils who had Helgi killed;
Hroar died and was succeeded by his son, Hrorik;
Hrorik fell in battle and Hrolf succeeded.

Now what will happen between Hrolf, Adhils, Yrsa and Svipdag? Only further reading will tell but not tonight.