During the mid-1st century BCE, Irsu worked as a tomb robber for a living, working alongside the corrupted official and Nomarch of Thebes Nome Tychon, frequently sharing his riches with him. They also worked alongside Athames, the strategos of Yebu Nome. This act however was not well received by his sibling, whom sought to turn him to be punished. As a result, Irsu had them killed and intended to kill their son Sutekh, but ultimately took him in.
In 38 BCE, Irsu discovered a relic in the tomb of Nefertiti in the Valley of the Kings. Intending to auction it for a large sum of money, Irsu took it from the tomb back to Thebes. In doing so, Irsu supposedly brought the wrath of Nefertiti with him, as apparitions of the pharaoh later appeared, killing and terrorizing the residents of the city. In reality, the apparitions were the result of an Apple of Eden used by the God's Wife of Amun Isidora. Around this time, Tychon's failure to pay Irsu for his haul led their relationship to turn sour.
Irsu later planned to sell off the artifact at the auction on a small island southwest of Thebes. However, the auction was interrupted by a group of guards under Tychon, who were led there by Sutekh. Amidst the confusion, Sutekh managed to steal the artifact away, but not without Irsu's men going after him. The tomb robber himself however, was captured by Tychon's men and brought to the Temple of Hatshepsut, where he was tortured for information about the relic. After being heavily wounded admist the torture, Irsu was found by the Hidden One Bayek of Siwa, who wanted information on the relic. Irsu told him what he knew before ultimately dying from his wounds.