What is the climax in the novel, The Old Woman With the Knife?

The novel's climax occurs when Hornclaw reports to the construction site per Bullfight's directive. As she wends her way through the site, trying to attune herself to her surroundings, Hornclaw comes upon three operatives, and she kills them all. Finally, she finds Bullfight on another floor with Haeni. The rivals battle in this location. Haeni eventually gets free, and Hornclaw ultimately kills Bullfight.