The Ending We Wrote

"It's not a bite," Cas assures. Dean knows. He cares about Cas too much; he would have shot first if he'd seen teeth on skin. But a bite isn't the only thing that kills. Getting stuck in the gut with rebar while scurrying away from undead cannibals will do the job just fine. One-shot, non-Endverse post-apocalypse, Cas/Dean.