He managed two steps. He was still roaring when the knife missile flicked past him, field outstretched.

It separated his neck from his shoulders. The roar turned to a sound like the wind, bubbling thickly through the exposed wind-pipe as his body crashed to the dust.

Faster - and turning more tightly - than any bird or insect, the knife missile made an almost invisibly quick circle round most of the riders, producing an odd stuttering noise.

Seven of the riders - five standing, two still mounted - collapsed into the dust, in fourteen separate pieces. Sma tried to scream at the drone, to make the missile stop, but she was still choking, and now starting to retch. The drone patted her back. 'There, there,' it said, concernedly. In the square, both of the inn-keeper's daughters slipped to the ground from the mounts they had been tied to, their bonds slashed in the same cut that had killed all seven men. The drone gave a little shudder of satisfaction.

One man dropped his sword and started to run. The knife missile plunged straight through him. It curved like red light shining on a hook, and slashed across the necks of the last two dismounted riders, felling both. The mount of the final rider was rearing up in front of the missile, its fangs bared, forelegs lashing, claws exposed. The device went through its neck and straight into the face of its rider.