The epilogue in the book of Judges presents the reader with two distinct historical episodes that each focus on a different issue. The main thing that connects them is the refrain: In those days there was no king in Israel; everyone did what was right in his own eyes.
This refrain appears in two forms, the one just cited (A) and an abbreviated version thereof (B): In those days there was no king in Israel.
The refrain appears in somewhat of a chiastic order:
A Judges 17:6
B Judges 18:1
B' Judges 19:1
A' Judges 21:25
This placement of the summary in its full form at the beginning and end of the epilogue and its partial form at certain points within the narrative is deliberate. It acts as a summary of specific events in the epilogue, and ultimately of the time of the judges as a whole.
Furthermore, the two narratives in the epilogue (Judges 17:1 – 18:31 and Judges 19:1 – 21:25) are further unified by five elements they share in common:
They both feature a Levite.
In both episodes the Levites have connections with a) Bethlehem of Judah; and b) the hill country of Ephraim.
In the first episode, the Levite goes from Bethlehem to the hill country of Ephraim. In the second, the Levite goes from the hill country of Ephraim to Bethlehem.
In both narratives, the actions of the Levites lead to serious consequences on the national stage.
The first narrative ends with a reference to the sanctuary of Shiloh (Judges 18:31); the second narrative concludes with the abduction of the daughters of Shiloh (Judges 21:19–23).
The epilogue is thus a single unit, and a literary masterpiece
at that.1
1 There was a man of the hill country of Ephraim, whose name was Micah.