In Philbrick's Freak the Mighty, the climax of the novel happens very close to the end of the novel when Kevin (Freak) dies.
A climax is:
the moment in a play, novel, short story, or narrative poem at which the crisis comes to its point of greatest intensity and is resolved.
Therefore, all of the conflict (the fighting with the Tony D. and his gang, the kidnapping of Max, and the hospitalizations of Freak) all lead up to the death of Freak.
After Freak dies, Max is able to understand what he must do to survive without Freak. Max has become stronger, learned about true friendship, and realized that he is capable of standing up for himself and others.
Therefore, the climax of the novel is Freak's death given the falling action and resolution are the places where Max comes to terms with everything that has happened over his time with Freak.
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