Pinion is Rose's 8-year-old younger brother. Later in the series, when Rose finally reunites with him, it is revealed that Pinion has an extraordinary ability to remember anything he sees and map it out accurately. For instance, if he walks through the hallways of a castle, he can later draw a detailed map of it.
Due to this unique talent, some researchers take Pinion from their aunt and uncle, who have given their permission for him to be taken. These researchers intend to use Pinion’s abilities to identify the weak points of their enemies' castles.
