The Walking Dead kicked off its fourth season with a new wrinkle: an illness that has killed at least one in the prison population in a very, very short amount of time. And you know what death means in this world: instant transformation into a zombie. I recently spoke with Vincent Martella, whose character Patrick - new to the show this season - is Patient Zero. When last we saw Patrick, he dropped dead in the shower in the middle of the night - then awoke almost immediately, zombified. We spoke about what kind of havoc Walker Patrick might bring upon the survivors.