The summon stone - Ian Irvine

The Merdrun, cruel warriors blooded by thousands of years of slaughter, are gathering in the void between the worlds.
Their long-hidden summon stone is waking, corrupting good people as well as bad, and turning arcane places into magically polluted wastelands. If it is not destroyed it will create a portal and call the Merdrun through.
In a nightmare, a nine-year-old girl sees the Merdrun leader - and he sees her. If Karan and Llian are to save their daughter and their world, they must find a way to stop the greatest warrior in the void.