He did the next logical thing — he smashed the rock to bits.

The impact wasn’t what he had expected — a loud CLACK, followed by a cluster of lesser CLICKs as fragments arced through the air and landed around him, and partly muffled by the screech of a seagull.  But it felt good.  His arms and stomach lost some of their tension.  And he was surprised — surprised that he enjoyed even a trivial act of destruction.  It was alien to him, as was the acknowledgement, and, moreover, the expression, of anger.