Callum's map was a map of the Plume Coteries' Library which came to be owned by Callum.
It was one of many "maps more wonderful than any which had been found near the Gate Rooms" which Auteur created during his time posing as the "Last of the Mappers". As such, despite folding down to a pocketable size, it could be unfolded to display any floor of the infinite Library. However, only Floors which had been explored by a Stocktaking Party were filled in, with others appearing as blank floor-plans with no clue as to their contents. Floor 899,167,435,042 had a note confirming that Master Librarian Roland had visited it, but was left empty because Roland had burned down its contents during that visit in an effort to kill Auteur, having realised who he really was.
258 years later, the yellowed and dog-eared map made its way into the hands of runaway Novices Callum and Maritsa, who used it to guide themselves through unpopulated parts of the Library as they fled from the Master Librarians with the rescued Coloth. Callum was the custodian of the map and was quite protective of it as he feared it was the main thing he brought to the table compared to Coloth's shapeshifting abilities and Maritsa's reliable practicality. It was briefly stolen by Master Librarian Naimon when he took the three prisoner, but was soon recovered by the children after Naimon failed to heed a warning from them and fell down an elevator shaft to his death. (PROSE: The Cactus and the Corpse [+]Loading...["The Cactus and the Corpse (short story)"])