Cions of Vega

Story-related; In the seventh and final main area, enter the only house here and head upstairs. Interact with the door to learn you need a key card, return outside and grab it from your brother. Then use it to open the door and read the letter on the table. Return outside and choose any of the responses to your brother to complete the game.

​​​​See Cult (50G) for a full video walkthrough!