Well, not so much a rule, as such, more of a general guideline.
A stone-tipped arrow went through her hat.
Hardly really a guideline, even.
In fact, not even-
Oh, drat.
She plunged into the lead horse's mind, down through the layers of barely controlled madness which is what is inside even a normal horse's brain. For a moment she looked out through its bloodshot eyes at her own figure, staggering through the snow. For a moment she was trying to control six legs at once, two of them in a separate body.
In terms of difficulty, playing one tune on a musical instrument and singing a totally different one[20] was a stroll in the country by comparison.
She knew she couldn't do it for more than a few seconds before total confusion overwhelmed mind and body. But a second was all she needed. She let the confusion arise, dumped it in its entirety in the horse's mind, and withdrew sharply, picking up control of her own body as it began to fall.
There was one horrible moment in the horse's head.
It wasn't sure what it was, or how it had got there. More importantly, it didn't know how many legs it had. There was a choice of two or four, or possibly even six. It compromised on three.
Granny heard it scream and collapse noisily, by the sound of things taking a couple of others with it.
“Hah!”
She risked a look sideways at Diamanda.
Who wasn't there.
She was in the snow some way back, trying with difficulty to get to her feet. The face she turned to Granny was as pale as the snow.
There was an arrow sticking out of her shoulder.
Granny darted back, grabbed the girl and hauled her upright.
“Come on! Nearly there!”
“Can't r'n . . . c'ld . . .”
Diamanda slumped forward. Granny caught her before she hit the snow and, with a grunt of effort, slung her over her shoulder.
A few more steps, and all she had to do was fall forward . . .
A clawed hand snatched at her dress . . .
And three figures fell, rolling over and over in the summer bracken.
The elf was first to its feet, looking around in dazed triumph. It already had a long copper knife in its hand.
It focused on Granny, who had landed on her back. She could smell the rankness of it as it raised the knife, and she sought desperately for a way into its head . . .
Something flashed past her vision.
A length of rope had caught the elf's neck, and went tight as something swished through the air. The creature stared in horror as a flatiron whirred a few feet away from its face and swung past its ear, winding around and around with increasing speed but a decreasing orbital radius until it connected heavily with the back of the elf's head, lifting it off its feet and dropping it heavily on the turf.
Nanny Ogg appeared in Granny's vision.
“Cor, it doesn't half whiff, don't it?” she said. “You can smell elves a mile off.”
Granny scrambled upright.