Profit and Loss is an Act 2 main quest in Dragon Age II. It is only available if the quest Friends in Low Places was completed during Act 1.
Walkthrough
Once exiting the Viscount's Keep, Bodahn Feddic will meet Hawke and reveal that he has been sent by Leandra to inform Hawke that a gentlemen called Dougal was waiting at the Hawke Estate.
Once entering the estate, Hawke will be visited by Aveline, after which Hawke will walk into the library, where Leandra is conversing with Dougal. Despite Hawke repaying him in full, Dougal wishes for a larger cut of Hawke's profit, namely one hundred sovereigns. Dougal threatens to spread "evidence" regarding the disappearance of Bartrand Tethras.
Hawke can either pay him the one hundred sovereigns or refuse his offer.
While travelling around Kirkwall, a random encounter will occur in which Dougal ambushes Hawke forcing Hawke to kill him and his men (820 XP & random loot from the bodies).