 In The Hidden Oracle, Percy states that Annabeth had gone to Boston for "some family emergency" — searching for her cousin Magnus Chase.Annabeth's appearances in crossover shorts with "The Kane Chronicles", and in "Magnus Chase and the Gods of Asgard" make her the only character besides Percy Jackson to have appeared in all three of the Greco-Roman, Egyptian, and Norse mythology series by author Rick Riordan.Her main weapon is a short celestial bronze knife given to her by Luke.