Obok, nicknamed Hidden Guard by prisoners, was a personal spy of the queen, sent into the penal colony to check state of affairs there. She placed her duty before everything else, but ultimately failed, dying alongside prisoners and fellow guards in the Atu's Siege.
Obok was hunter in her early years, but, after a fateful goblin attack, dedicated her entire life to becoming a fearsome warrior. She was zealous in her servitude, had absolute loyalty and received a great deal of respect from the queen herself. Quickly, she was moved from the sentry duty to spy job. Although she refused to even mention it, her outstanding skills with axe and observation spoke for herself pretty well.
When Obok was sent into Steelhold, she went as far as even being married to the Bomber and lied about having children - too small to be convicted alongside their parents. Probably it was just facade, as she wasn't that sad when her husband hit the dust. But she may have had some feelings under her cold surface of a no-fun warrior after all.
Obok arrived at penal colony during Sarrak's shadow reign on 25th Slate of year 252, somewhat spoiling Mad Butcher's plans with ever-watchful eyes. State of affairs was far from desired, with Warden completely discarded aside and prisoners slowly coming into the position of power. At first, Obok tried to pose as a prisoner herself, fisherdwarf by trade, but to no avail - she couldn't hide her arrogance and military skills. Then, she became a full-fledged member of Steelhold Guards.
Obok died alongside Warden in the ill-fated attempt to break siege, laid to Steelhold by Atu, thus removing last traces of guardian presence in the fortress and leaving her liege without insight onto state of colony affairs. The last part would ultimately lead to rather interesting events in future years.