Your character must initially come to grips with this thing that’s happened to them. In National Treasure, Ben Gates discovers that his treasure hunting partner is completely unscrupulous. His partner will steal the Declaration of Independence, one of the United States’ most beloved documents, and Ben has no confidence he’ll ever return it.
So Ben goes to agency after agency–FBI, Homeland Security—trying to convince someone, anyone, that there’s a real threat. And he’s dismissed as just another nutcase.
In How to Train Your Dragon, Hiccup is a scrawny Viking trying to fit in and get noticed by a girl. He plots different ways of killing various dragons, so he can finally be accepted by his village. Because he’s mechanically inclined, he comes up with a catapult that will capture a dragon so he can kill it.
If your heroine is diagnosed with breast cancer, she might struggle with telling her family and friends. She might search the internet to find doctors who will offer the best chance for a cure.
Protagonists don’t always cooperate in this stage of the novel. Sometimes they rage against their fate. If it’s a romance and the protagonist is already in an unsuitable relationship, she may provide reasons for why everything is really okay with the love interest she already has.
Then comes the decision—also known as the point of no return. It’s also called the first plot point, but I dislike that label because it conveys no information. In Star Wars, once Luke decides to leave the farm and go to Alderaan, his life will be forever changed.
Similarly, in National Treasure, after Ben Gates has tried and failed to convince everyone in authority that there’s a real threat to the Declaration of Independence, there’s a scene where he’s standing in front of it, at his wit’s end as to how he can protect it. He turns to his friend and says, “I’m going to steal the Declaration of Independence.” That decision marks the end of act one.
And in How to Train Your Dragon, when Hiccup discovers Toothless, and worse, finds that he can’t kill him, he crosses a line. There are more important things than trying to fit in. Saving this dragon is more important than gaining the approval of his family and friends.
Often the stakes deepen at this point as well. Luke discovers it’s not all about rescuing a beautiful princess; the Empire is quite willing to kill anyone who stands in their path. Hiccup’s father, who up until this point only been distant, now demands that his son go to class and learn how to kill dragons, just as Hiccup discovers he can’t. Ben Gates could very well go to prison if he attempts to steal the Declaration. But even though the stakes intimidate your protagonist, they decide it’s worth the cost.
Somewhere before or at a quarter of the way through your story, your protagonist has to stop being moved by events, and become an active participant instead. This requires a decision on their part—a decision that must be backed up by action.
Without this decision, you have a passive protagonist, one who is merely carried by the plot, rather than one who makes the plot happen. Readers admire characters who act. Make certain your character decides to do so—and then follows through.