Mrs. Zapata is Dan Cahill's Social Studies teacher. The students call her Mrs. Zzzzzzz.
Her first and last appearance is in Vespers Rising, where Dan is not paying attention to her while she is talking about Nefertari. It has been revealed that before the Clue Hunt, Dan used to humiliate her by turning her cheeks magenta, but the Clue Hunt has changed all that.
When Mrs. Zapata was briefing about Nefertari, she showed pictures of the other female empress Nefertiti's side chamber, claiming that it was part of Nefertari's tomb. Dan, having visited Nefertiti's tomb, knows naturally that it was Nefertiti's side chamber. He tells Mrs. Zapata that. However, Mrs. Zapata denies it, claiming that Dan had no evidence to show that, and he could not possible have went there. Dan, who was not allowed to spill the beans about the Clue Hunt, could not bite back, and soon stopped paying attention to her again.