Osquith is an employee of the Incorruptible Republic of the Immortal Library of the Grand Architect, which is located underground beneath Paris. He is a stout bearded gentleman of meager height who wears a black beret with a red ribbon tail and a fur trimmed double-breasted green jacket.
Osquith is the first member of the Library to greet Larana Chroma and Agatha Heterodyne's group upon their entry of the Library. Larana entrusts him with her unconscious father who is The King of the Silver Lands and has been collaborating with Geisterdamen and aiding in their conspiracy to wasp the underground and Paris. Osquith then introduces Agatha to Melissa Solera and Jon Solera, the Grand Curators of the High Western Stacks.
Osquith is last seen on the very page of his introduction after presenting Agatha to the Soleras who were heading the Library while The Lord High Conservator is out of the Library. Little is known about him except that he was not one of the wasped members of the Library as Agatha's Wasp-Eater does not react to his close proximity.