In this short scene, we learn that the Fort is about to shrink, and that the safe zone will soon be filled with enemy soldiers. This is a good thing, because it means that the enemy soldiers will be able to hold the fort for a while longer, and then the Fort will be overrun by the rest of the party. The only problem is that this is a new battle royale game, and the damage is not caused by a poisonous gas. Instead, it's caused by "radiation" , which is the same thing as a poison gas, except that it causes a drop in one's health. So, the only way to stop the enemy from killing you is to set traps in the area where you're hiding, and wait for the enemy to come out and kill you. The plan works, and now that he knows why, he's free to join the party as he pleases.