Family Meeting is one of the main quests that you get from Thorald during the third chapter of Elex. This quest starts with a conversation with the hero's father. After that you must search for Kallax. This means that you will have to meet with a huge group of powerful enemies.
How to unlock this quest: Speak with Thorald in Abandoned Cliffs.
You must meet with the hero's father – Wardek. The man stays in Albs-separatists' hideout in Converter in South Abessa. Speak with Wardek (800XP) and you will learn about whereabouts of Kallax, Jax's brother.
Head to a base in mountains located near Converter in North Abessa. You must reach one of the rooftops of the buildings that are presented in the picture. Use your jet pack to reach it. You should also save your game here because after reaching the appointed place (8000XP) you find out that you are in Kallax's trap. Don't try to fight the enemies sent by Kallax (Fighting Colossus mechs, Albs soldiers, Combat Robots) if your character isn't very powerful. Quickly jump down from the rooftop (use your jet pack to safely reach the ground) and leave this place as fast as possible.
Go back to Wardek in Converter in South Abessa and demand explanations (1400XP). He gives you a location of a fishing village and suggests you to visit that place. Berserker Island is located in the south end of Edan, the picture above shows this location. You must swim there because there is no bridge that leads there. When you reach this place Jax will remember events from his childhood (1400XP). You can leave this place immediately or meet with Katta and start Exiled Unjustly side quest.
Meet with Wardek again. You can choose how you want to react to Wardek's actions – taking Jax and Kallax from the Berserkers village.