Immortality

This was perplexing. Rem had never had someone fail to die before.

Nonsense, Rem thought, he'll die. Someone can't just refuse to die after being stabbed repeatedly through the heart.
Suddenly, as if reading Rem's muddled thoughts, the boy spoke.
"I'm not gonna die you know." The boy bitterly groaned. "That should be apparent by now."

-----

Rem's night plan of an easy assassination and a restful night's sleep afterwards is immediately ruined when his victim
refuses to die. No matter how many times Rem stabs him, he just won't die!