Chapters Twenty, Twenty-One, and Twenty-Two Summary

In Chapter Twenty, that night Petra reviews all that happened at Delia Dell. She wonders at Ms. Hussey and Mrs. Sharpe's connections to the crime. She begins to think her imagination is running away with her. In the bath she imagines a rectangle inside of a triangle. She then wishes she could stop thinking. The next morning she wakes refreshed. She feels much more sure about the truth her imagination gives her than she was feeling the night before. As she walks into the kitchen, she sees horrified looks on her parents' faces. The thief demands that attributions to Vermeer be changed by January 11th, or he would destroy The Lady Writing. Petra drops the paper and rushes out of the kitchen.

In Chapter Twenty-One, the thief is discovered the be more ruthless than the...