When her granddaughter Aria comes to stay with her, making it her mission to turn her boba café around, Jing Li, who is the secret keeper of the monster of San Francisco, is overrun with customers while Aria sneaks away to reason with the earthquake-causing monster.

"Lucia Castillo dreams of being a hero like her grandfather. But to the people in their Texas town, he was just a strange old man who dressed up as a knight and claimed to save the world from monsters only he could see. Now years later, when Lucia and her best friend--and trusty squire--Sandro discover the town mayor is secretly a shapeshifting beast of Mexican lore, her parents think she's imagining things like her "Abuelo Loco." Only Lucia, wearing...