"Gas Mask Man" is a side quest available in Dying Light.
Infected broke into the fishing village. Musa says the gate was sabotaged by someone in a gas mask, who lives outside of the village. These people are paying Rais for protection, and since I'm one of Rais's apes now, I guess i'd better talk to this "Gas Mask Man".
- Find Gas Mask Man and talk to him
- Gas Mask Man is clearly unhinged, but he swears it was someone else who sabotaged the gate. He'll tell me what he saw if I can recover his "treasure bag", which fell in the lake.
- Recover Gas Mask Man's treasure bag
- Bring the bag to Gas Mask Man
- Gas Mask Man spotted one of the fishermen sabotaging the gate while wearing a gas mask. He couldn't identify him, but whoever he was he must have a key for getting in and out of the village. The guards will know who has such a key.
- Talk to the guard
- Three people have a gate key: Tom, Gursel and Musa. I should search their huts for evidence.
- Search Tom's house
- Search Musa's house
- Search Gursel's house
- Gursel sabotaged the fence. I want to know why. I'm going to confront him before telling the others.
- Talk to Gursel
- Gursel thought allowing infected to break in would show the villagers that they're vulnerable and in need of Rais's protection. It seems Rais has a way of making good people make bad decisions.
- Talk to Musa
Starting the Quest
In order to continue, Kyle has to go talk to Shakur (who's out of town holed up next to a river) and he tells Kyle that someone was disguised as Shakur, and Shakur didn't really do it. However, Shakur doesn't reveal who the person disguised as Shakur was unless Crane gets Shakur's bag of valuables found at the bottom of the nearby river. Once Kyle throws over the bag to Shakur, he tells Kyle that he doesn't exactly know who did it, but it was one of the fishermen residing in the village.
Wrapping it Up
Talking to a guard next to the village main gate reveals that only three people have keys to open the main gate. Crane is now tasked with searching Tom's hut, Musa's hut and Gursel's hut for a gas mask. The mask is located on a washbasin in Gursel's hut. After finding the gas mask, you have to go talk to Gursel. After talking to him, going over and talking to Musa completes the quest and you are rewarded with the exceptional Champion weapon upgrade.
When you first talk to Shakur, a new Safe Zone is opened up for you. That Safe Zone will become obsolete and will no longer be safe from enemies upon completion of the quest, with Shakur having abandoned the place and there are no other survivors.