Fern was a Deltoran woman who was imprisoned and taken to the Shadowlands to work as a slave. She was brainwashed into becoming a secret servant of the Shadow Lord. Once she was freed, she joined The Masked Ones.
Fern and her husband had been kept in the Shadowlands for years as slaves. She was branded on her left cheek, leaving her horribly disfigured. At some point before King Lief freed the slaves, she became a secret servant of the Shadow Lord.
Fern and her husband joined the Masked Ones upon their return to Deltora, and while disliked by the members of the Inner Circle, Fern was happy for the mask to hide her face.
Fern met Lief, Barda, and Jasmine when they joined the Masked Ones on their way to Shadowgate and told the companions about her story. When the troop passed through Happy Vale, she was informed of the companion's true identities through a coded message left by Kirsten, and ordered to steal the Belt of Deltora. She convinced Zerry, a magician apprentice, to steal the Belt and sell it to a man by the Riverdale Signpost.
Later, she attempted to search through the companion's belongings and was attacked by a projection of the Masked One. Lief and Rust arrived to see the phantom vanish, and Fern warned Lief to beware the Masked One before she died.