Abel was like his sheep the same flat, complacent gaze, the thick curls low on the forehead, a voice like the creak of new shoes when he prayed. The prayers were invariably answered. His flocks fattened, and the wool fetched top price. His warts disappeared overnight. His advice to his brother, Cain, was invariably excellent. Cain took it about as long as he could and then let him have it with his pitchfork one afternoon while they were out tedding hay.
When God asked Cain where Abel was, Cain said, "I don't know," which didn't fool God for a minute, and "Am I my brother's keeper?" which didn't even rate an answer (Genesis 4:9). Even so, God let the crime be its own punishment instead of trying to think up anything worse: with no stomach for haying that field anymore, Cain took up traveling instead, but lived in continual fear that he'd be spotted as a fratricide and lynched.
When he complained to God about this, God gave him some kind of severe facial twitch that marked him as the sort of man you don't kick because he's down already and thus ensured him a long life in which to remember that last incredulous bleat, the glazing over of that flat, complacent gaze. The justice and mercy of God have seldom been so artfully combined in a single act.