"Sister" in Dying Light 2

To take this quest, you need to complete the story quest "A Place I Call Home". The reward depends on how exactly you decide to complete the mission.

To start the quest, talk to the old man who is located west of the Waterside subway. Go to the dark area in the marked place, in the center of the city. Go inside the location and kill the bandits. Then go up to the second floor where there is a locked gate you can interact with.

After that, go north to the windmill and talk to the girl. You will have two options that will affect the reward:

• Pretend to be a grandson so as not to break an old man's heart. You will receive 1500 combat and parkour points and 3 UV lamps.
• You can admit who you really are. Then get 1500 experience points and only one UV lamp.