Answer:
It gives O. Henry a way to keep key information about both main characters hidden until the end
Explanation:
"After Twenty Years" is a short story that was written by O. Henry about two friends who separated and went in different directions for many years and got reunited.
They decided to meet at a restaurant later that same day but the narrator's use of the third-person narrative helps him to keep vital information about both characters until the very end which gives the story a plot twist.