This is when, just before the third act and when things are at their worst, the protagonist is abandoned by their best friend. Here's how it normally plays out: It's been a long, hard road for the protagonist. They've fought their way through rising complications, twists and turns, and unexpected outcomes, yet are the furthest from achieving their goal since the story began. Good thing they have their best buddy to help them when all other lights have failed. Expect a change of heart and a last minute save by the best buddy in the climax, thus reinforcing The Power of Friendship.