A time-travel adventure rich with religious and cultural details opens with 21st-century fifth-grade cousins Ava (Jewish) and Nadeem (Muslim) at their grandmother’s. After hearing that Ava barely avoided getting into a fight when friends suggested that it would be better if she and Nadeem didn’t hang out at school, Granny Buena tells the story of their distant relative Ester ibn Avram, a Sephardic Jew. As a girl in 775 CE, in what is now Morocco, Ester helped Abdur Rahman escape into Spain after his ruling family was deposed in Syria. Granny shows Ava and Nadeem the jeweled pin (button) that Rahman gave Ester for helping him escape. That button is the portal that transports Ava and Nadeem, along with Granny’s cat, Sheba, to the North African city of Sabtah, where young Ester and her family live. They arrive just as Abdur Rahman is seeking help. Ester, small for her age but mightily determined to be taken seriously—a challenge due to her size and gender—is aided by Ava and Nadeem, whom everyone mistakes for her visiting cousins, in fulfilling Abdur Rahman’s request for assistance. This breezy, swiftly paced story is followed by authors’ notes. Abdur Rahman is a historical figure who ushered in a period of enlightenment when he was ruler of Spain. Ester is wholly fictional. (Ages 7-10)