`` sir , someone is coming , '' digby said , pointing , and the debate was moot : a courier-dragon was coming quickly from the city , with an escort of two heavy-weight beasts ; and though the lowering sun was full on them , blotting out their colors , laurence saw clearly silhouetted against the sky the two great horns thrust up from their foreheads , the narrower spikes like thorns bristling along the twisting serpentine lengths of their bodies : he had seen a kazilik once before thus , framed against the billowing tower of smoke and flame rising from the orient , at the nile , as the dragon set her magazine alight and burnt the great thousand-man ship to the waterline .