Hypothetically, let's say you have a friend who is totally incompetent, but you hang out with him just for laughs. One day, there is a large-scale zombie invasion, and you and a couple of other friends, much more competent than the afore-mentioned, all get together. Your loser friend is also with you, and early on he already shows signs of mental instability. He is a stress-eater, screws up everything you tell him to do, and you are beginning to be afraid of letting him have a weapon, lest he turn it against one of you. Still, he's always been there for you ever since you were kids, and you owe him for saving your life once... what do you do?