AustLit

'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.'

Source: Publisher's blurb.

'The cruel Merdrun, the greatest warriors in the void, have invaded Santhenar but their portal failed, leaving them stranded. They're desperately trying to regain contact with the summon stone so they can reopen the portal and begin the slaughter of humanity. Llian, hurled through another portal, sees the summon stone wake and knows the allies have but one chance to destroy the Merdrun - though it will involve an alchemical quest that has always ended in ruin, a mad invasion in untested sky ships with untrained pilots, then the most unequal battle in all the Histories.' (Synopsis)

'The ferocious warrior race, the Merdrun, have finally succeeded in invading the beautiful world of Santhenar, in the culmination of a plan they’ve been working on for ten thousand years. But they have only fifty-five days to build the Sapphire Portal, the greatest tower in the history of the Three Worlds, and put their dreadful plan into effect. 

'Karan, Llian and their dubious and untrusting allies have only fifty-five days to destroy the reborn  summon stone that gives the Merdrun their power. Fifty-five days to develop their daughter Sulien’s magical gift and unlock the hidden memory that could reveal the Merdrun’s one fatal weakness. Fifty-five days to save her life.

'But Sulien has been abducted, along with dozens of other gifted children and a hundred thousand adults, all enslaved to build the mighty portal in time. To save her life, Karan faces the most difficult choice of all – going into the enemy camp and becoming a helpless slave herself.' (Publication summary)