Kill
Kill, an action that is unforgivable and an action that may save your life.
He knows several ways to kill, either be it slow and painful, making the person smile when the time finally came or quick and simple, never letting the person know what had hit them.
There are many methods to kill people, some of them can even bring the strongest ones down to his knees, yet without leaving any marks or scars on his body.
Still, he didn't know what she had meant, when saying that he was killing her.
He knew that he didn't do anything to make her come out with that statement, never had he raised his hand against her or do something that could break her spirit. So at first he thought that maybe it was some girl thing, and didn't think further over it.
"I love you," she says with a big smile and shinning eyes, putting at lot of feelings in those three words.
"Thanks" he reply, and immediately, he find the glint in her eyes gone, but she is still smiling. Without any other words she leaves the room, turning his attention back to his drawings, he wonders if it's because of the 'thanks' he always reply whenever she with a big bright smile says "I love you"
But then again, how would he know how to respond to that?
So he finds the easiest thing to do is smile and say "thanks" or "thank you", even if it was killing her.
Four letters, separately they can't do anything, together they can be the end.