What parts of "An Occurrence at Owl Creek Bridge" are understood as being in real time vs. imagination?
This story is complex in structure and point of view as Bierce moves the reader between external events and Peyton Farquhar's thoughts. It is only at the story's shocking conclusion that we realize much of what "happens" in the story did not happen at all, except for a few seconds in Peyton's mind.
Part I chronicles events in real time. Union forces prepare to hang Peyton in the middle of Owl Creek Bridge. A rope around his neck, Peyton stands on the end of a wooden plank laid over the bridge's crossties; a sergeant stands on the other end. If the sergeant moves off his end of the plank, Peyton will fall through the floor of the bridge and be hanged. At the end of Part I, "The sergeant stepped aside."
Part II is a flashback that relates the past real events that led to Peyton's hanging.
Part III continues in real time with Peyton's body falling through the bridge. It is at this point that Bierce moves us from real external events to real events inside Peyton's mind: "From this state he was awakened--ages later, it seemed to him . . . ." Bierce then takes us through Peyton's physical sensations as he is being hanged. Suffering intensely, Peyton's mind moves next into imaginary thinking (the rope breaks). Peyton's escape does not actually happen. Finally, as he reaches for his wife (imaginary), he feels "a stunning blow upon the back of his neck." With this, Bierce returns to real time as Peyton's falling body reaches the end of the rope, breaking his neck.