On the right side of the square in the main section of Riverford, you will find a man with a passion for treasure hunting, who is looking for the lost loot of the former House Landar. There are two options that you can do to complete this quest, with the first solution being in Atlasdam. As soon as you enter the town, go south, down the stairs and find the Erstwhile Retainer. Steal/Purchase the House Landar Records from the gentleman, then return them to the questgiver to finish.

For the other solution, you require the Path Action of either Alfyn or Cyrus. Travel to Stonegard and look for the Erstwhile Bodyguard, who is on the right side of the fountain in the Heights section of town. Inquire/Scrutinize The Fall of House Landar from him, then return to the questgiver to finish.