An excessively chatty boy known for his love of jokes, often seen as annoying by peers, who uses his keen logical skills to decode and mediate challenging situations alongside Cass.

A main antagonist driven by the quest for immortality, she leads the Masters of the Midnight Sun while hiding her true age behind a polished, but deceptive, exterior.

Another key antagonist with a hidden identity linked to a familial relationship with a member of the Terces Society, revealing emotional complexity despite his villainous pursuits.

An absent mentor whose influence through his writing guides Cass and Max-Ernest, he plays a significant role in granting them access to the Secret world and acknowledging their talents.

An enigmatic character who directly engages with the reader, adding to the mystery and interactivity of the story while revealing his own conflicted nature.

An artistic misfit with synesthesia who perceives the world in unique sensory overlays, his intricate paintings are misunderstood by peers but speak to his innate connection to the Secret world.

Cass’s unconventional yet supportive substitute grandfathers who run a mysterious antique shop and offer a blend of belief and skepticism in her adventures.

A probate specialist known for her materialistic tendencies, she inadvertently links the main characters to the magician's mysterious world through her involvement with his estate.