He was assigned by his father to verify the security of each major hold in Skyrim. Gabriella sends the Dragonborn to eliminate him, hoping to weaken his father's leadership and distract him from his duties to the guard, thus leaving the Emperor vulnerable to an assassination attempt. The Dragonborn was to murder him in one of the cities and plant an Incriminating Letter on his corpse. The letter describes a thwarted assassination attempt, meant to further leave the Emperor unsuspecting of an assassination attempt.
Gaius Maro followed a specific schedule, departing from Dragon Bridge and traveling to each major hold in Skyrim. He was also assigned to monitor Windhelm's security and even sleep in the barracks despite the ongoing hostilities between the Stormcloaks and the Imperial Legion.
After his death, his father, Commander Maro, apprehended the Dragonborn Listener and attempted to murder them. Astrid, leader of the Falkreath Sanctuary, sold them out, feeling threatened by the Night Mother's authority. Commander Maro burned the Sanctuary, killing several of its members in hopes of avenging his son's death.
- The Elder Scrolls V: Skyrim (First appearance)