You were surrounded by zombies, they seemed to multiply with each one you killed. You were strong, you’ve survived on your own for months now, but they were wearing you down and didn’t seem to be wavering.

A sudden object fell from the roof above, you had just enough time to see it was a smoke grenade. Hands grabbed you as it went off, the zombies left in confusion like you.

Who was this, and what was going on?