Before referencing Melville, just a word on Chapter 27. There are two events going on this chapter. One, of course, is the progression and inevitable results of the Dunk attack. Rocky is coming down with Dunk Fever and unless she gets back home and is successfully treated, she will die. The other event is the Peregrine Falcon, Juniper.
So again from the reference point of the mythological hero, Rocky has to go home because she did not go through the Threshold of Adventure (the Rusty Scuttle.) And she has been dealt a potentially fatal blow because of this (Dunk Fever) Then, of course, the Peregrine enters the picture. The Falcon will come into its own in Book Two and will be a powerful aide to Rocky but before the bird can enter the picture, Rocky has to agree to go home. The Falcon then, to put it one way, is her reward for "playing by the rules."
So on page 147 of this chapter, this important moment comes up. I wrote this in proper sequence and close in proximity to emphasize this point. The first part of the equation then is Rocky's decision to go along with Charlie's insistence that she return to Port Thomas. Here that is:
Charlie again spoke. "I mean it, you know. We're leaving in the morning and we're not traveling west to the headwaters." Rocky started cleaning the pot of stew and putting things away.
"Fine, she finally said, with a bit of a pout on her lips. "Are you at least going to let me stay tonight or should I get going right now?"
"Don't be silly. I'm going to get some firewood."
Right after Rocky makes up her mind to return to Port Thomas, her "reward" appears (the falcon)
Here is that:
It was a about that time that a certain peregrine, still hiding in the small rock covered hiding place, made her presence known.
The events that follow in this chapter, involve rescuing the Falcon and getting the injured bird to cooperate in the transport home.