Barnibus works for the Watchful Order of Magists and Protectors, investigating crimes that involve the use of magic. He comes across as prickly and secretive, confiding only in Saeth Cromley, a retired sergeant of the City Watch who assists in many of his investigations.
 
A lifelong bachelor, Barnibus has a small, tidy estate in the Sea Ward that he inherited from his grandmother. When not serving the Watchful Order, he spends his days reading and writing books in the library.
 
Barnibus uses spells that help him investigate crimes, pry secrets from the mind of suspects, and locate missing persons. He finds violence appalling and would never use his magic to inflict harm on others - even those who would harm him.