During a flashback at the beginning of The Golem's Eye, the Staff is shown to have the power to summon powers from the skies for additional destructive power, sending arcs of white lightning hurtling into anything Gladstone directed it at. During the flashback, the staff was used to break the Wall of Prague and leave the woebegone former Empire to the mercy of the British army. It was later used by Nathaniel to try and destroy the Golem; however he failed to fully understand its activation incantations, and simply succeeded in shocking himself into unconsciousness.
During the events of Ptolemy's Gate, the Staff had been placed in the Vault of Treasures below Whitehall, along with the Amulet of Samarkand and other notable treasures. The Staff was to be procured by Makepeace after his successful coup d'etat. However, his mind, along with the minds of his fellow conspirators, were crushed and their bodies taken control of as part of the great Spirit Rebellion. The Staff was retrieved by Nathaniel, the newly reformed John Mandrake. After summoning Bartimaeus into his body, the two harmonized their actions and were able to successfully use the Staff to lay waste to the majority of the Human-Demon Hybrids, including the long-time enemy of Bartimaeus, Faquarl.
At the end of the book, the Staff was destroyed and its inner spirits released when Nathaniel, in a last-ditch effort to defeat the Spirit Lord Nouda, dismissed Bartimaeus from his body, unleashing the full power of the Staff, which caused a wireframe of iron beams and girders to fall and kill the demented spirit. The Staff, upon losing its spirits and along with them the source of its immense power, was presumably vaporised in the attack.
The Staff is described as being a tall, thin staff of dark mahogany wood. The head of the staff has a round knob at the top, with a small pentacle etched into it, where the captive spirits are compressed to focus their powers.