Vogler, Memo From the Story Department:
Something shakes up the situation, either from external pressures or from something rising up from deep within, so the hero must face the beginnings of change.
Something happens that upsets the balance of the hero’s life and presents a challenge or call to adventure. This is the Inciting Incident of the story, and it can either be causal (a result of an active choice made by your character) or coincidental (something unexpected, random, or accidental happens).
Batty - Movies that Move Us:
Physically, an event or set of plot-related situations calls the protagonist to undertake a journey: a physical crossing from Ordinary World to Special World. The event or set of situations, whether manifested through reality, fantasy or dream, acts as a message to the protagonist, willing him to take the steps necessary in order to leave his Ordinary World. As such, the Call to Adventure summons the protagonist away from his current existence. It is a turning point where the physicality of the Ordinary World is called into question: why stay in the familiar and exhausted place when you can enter the fresh and new?
Vogler, Memo From the Story Department:
With Increased Awareness the hero, through a Call to Adventure, begins to realize change is urgently needed but still doesn't know what to do about it.
Palmer - http://www.crackingyarns.com.au/2011/04/04/a-new-character-driven-heros-journey-2/
Step 2: Unsettled (Call to Adventure)
I’m comfortable with the term “Call to adventure” and I use it rather than “inciting incident” but that word “adventure” might discourage writers of dramas from thinking that the Hero’s Journey has something to offer them. This “adventure” doesn’t have to involve guns, high-speed chases or some mystical medieval text. It can just be a problem or an opportunity.
Like in Winter’s Bone, for example. Ree (Jennifer Lawrence) needs to track down her crack-merchant father for the rent money, or she, her younger siblings and incapacitated mother will lose their house.
The emotional effect of this Call on the protagonist will depend on whether they want this adventure or not. Indiana in Raiders of the Lost Ark, Ned (William Hurt) in Body Heat and Olive (Abigail Breslin) in Little Miss Sunshine are all thrilled to get the call so they’ll be excited.
But, more often, the Hero doesn’t want the call.
Bertie (Colin Firth) in The King’s Speech is resistant to the unusual techniques, not to mention the impertinent manner, of Logue (Geoffrey Rush); in Toy Story, Woodie hardly welcomes Buzz Lightyear with open arms; and Juno (Ellen Page) isn’t thinking about the miracle of creation when her third pregnancy test confirms the positive reading of the previous two. If the hero doesn’t want the call, they’re going to be disturbed at least, and quite possibly entirely mortified.