It was my fault that Adam became a zombie.

I see it in slow motion when I close my eyes: his hand reaching out to slam against my chest and push me into the wall as he throws himself between me and the oncoming Infected. I still see the sticky spiderweb of drool and blood stretching between its teeth as it comes at us with gaping mouth and hollow eyes and I still hear the crunch of tooth on flesh as it latches onto Adam’s bare shoulder.