Defective Zombies

Hang on!

We have a small problem here. You see, one of our experiments didn't go well. The newest zombies weren't up to our standards and now these rejects are shuffling all over our testing grounds.

We'll have to clean the place up, so you need to kill 4 defective zombies. Will you do it for us?

And please don't destroy any good ones while you're at it! We have a shortage of materials and every successful experiment needs to be preserved.

How are things at the testing range? Is it clear?

Great, the situation at the range is back under control. I know it was a dangerous job, but somebody had to do it! You sure are one tough soldier!