The merchant Thoronir is up to something, but Jensine and the other shopkeepers don't know what - it's time to investigate in the Unfriendly Competition quest.
The article on VG247 provides a detailed guide for the "Unfriendly Competition" quest in the rumored remastered version of The Elder Scrolls IV: Oblivion. In this quest, players are tasked with helping a merchant named Thoronir by investigating his suspicious supplier, a character named Agarmir. The guide outlines the steps players need to follow, starting with speaking to Thoronir in the Imperial City's Market District, then tracking down Agarmir, and eventually uncovering a secret operation in the abandoned house. The walkthrough includes specific dialogue options, locations to visit, and actions to take, such as pickpocketing and lockpicking, to successfully complete the quest and receive rewards.