Hal Kamhout is the Book Burning Officer (焚書官, Funsho-kan) and key-keeper of the Long Lost Library contained within the Silver Biblioprinchess Flamberge. His mission drives him to locate and destroy Phantom Books, artifacts of forbidden knowledge he deems bring only suffering to humanity. This duty stems from a tragic past where he lost a woman precious to him—implied to have died by his own flames—forging his self-destructive conviction that he too will eventually vanish in the fire of the Staff of Surtr, a fate he accepts.

His background reveals he once studied in a university laboratory, aspiring to travel to America for academic pursuits. During this period, he knew Francesca, later Flamberge, who resided in a nearby clock tower. The outbreak of war shattered these plans, and the loss of his loved one led him to become a Libricide Officer.

Hal maintains a consistently calm, focused, and emotionally reserved demeanor, though interactions with Flamberge provoke visible frustration. Their dynamic is contentious; he frequently silences her accusations with the phrase "Keep your mouth shut, you piece of junk," reflecting their antagonistic yet codependent relationship. Despite his grumpy exterior, he occasionally displays subtle empathy, such as sparing a smile after resolving incidents involving Phantom Books. He harbors deep disdain for Biblioprincesses and other key-keepers, viewing them as enablers of chaos, and particularly despises a figure known as "the Professor."

Physically, Hal is a tall man in his mid-twenties with sharp features, a perpetual frown, and a deep wrinkle between his eyebrows. His appearance varies: the light novel and manga depict him with ashen hair tied back, leather boots, and a long coat resembling a cassock or bounty hunter attire. The anime shows him with short brown hair, glasses, deep green eyes, a dark blue coat with yellow details, fingerless gloves, and a wide-brimmed hat. In the spin-off *Dalian-chan's Bookshelf*, he wears a black coat with a high collar.

His primary weapon is the Staff of Disaster of the Fire Giant Surtr (炎の巨人スルトの災厄の杖), a metallic staff with a censer tip. To activate it, he places a Phantom Book from Flamberge's library into the staff's head, declaring "Cartridge Load – Blaze!" This summons blue flames that incinerate the Phantom Book and all associated memories in those it affected. Using the staff requires him to unlock Flamberge's straitjacket using golden keys magically sealed in a crimson jewel on his right hand—a process depicted as painful in the anime. Hal is also proficient in Baritsu, an oriental martial art, which he employs in combat against Phantom Book users.

His story arcs demonstrate his methods. In "Libricide," he investigates a town controlled by sentient dolls created via a Phantom Book. After confronting the user, Mabel Nash, he burns the book and her corrupted memories, acknowledging his inevitable demise as part of his duty. In "Book of Atonement," he tracks a Phantom Book terrorist targeting post-war reconstruction efforts. Hal operates from a military motorcycle with a sidecar, emphasizing his mobile role.

In the spin-off *Dalian-chan's Bookshelf*, Hal shows marginally more openness to interaction but retains his brusque demeanor.