The Runaway Son is another side quest in Replicant. This guide on Where To Find The Runaway Son In NieR Replicant Ver1.22 will guide you through the quests multiple phases including finding the location of the lost son and the follow up objective that requires some basic materials.
Depending on where you are at the moment, it may be a better idea to grab the Goat Meat and Mutton before you begin the rest of the quest. You need to find 5 pieces of Mutton and 3 pieces of Goat Meat. Both Goat and Sheep can be found in plentiful supply in the Northern Plains. Kill a few of those and make sure you have the meat as it will make the second stage of the quest a little bit faster.
Where To Find The Runaway Son In NieR Replicant Ver1.22
Once you have the meats to complete the second stage of the quest, you can go ahead and complete the first step. You need to head South to Seafront, the small village by the sea, funnily enough. Once you’re there you want to head to the East side of town. You can use the bridge or jump across the small boats.
Once you get there you need to head towards the docks. Just before you reach the docks there’s a man with a strange hat standing by a tree. Speak with him, this is the runaway son. This will complete the first step of the quest, then you simply need to head to the Tavern before returning to your village to speak with the father. Once you return to the father you learn the son is a bit of a scam artist and you need to track him down again.
Return to Seafront and speak with the Resident by the Northern entrance. You will learn the boy has fled to Facade. Head to Facade and speak with a character at this location
Then interact with the nearby door to find the boy again. Once he flees, leave the town and follow him across the desert.