Elizabeth Struthers Malbon, In the Company of Jesus: Characters in Mark’s Gospel (WJK, 2000), 209.
In addition to their significance in extending the continuum of responses to the Markan Jesus, minor characters often appear at significant points in the narrative. Especially when Mark’s Gospel is heard rather than read, certain stories of minor characters serve to “punctuate” the narrative….Most familiar are paired stories serving as “parentheses” around a larger narrative unit. Other examples include stories functioning as “exclamation points” to indicate surprising end points or conclusions, or as “colons” to direct attention to narrative material that follows as an explanation or spelling out of implications.
The Amateur Exegete 