The Rise of Magicks (Chronicles of The One 03) by Nora Roberts

On the shield, one of seven forged in the timeless past to hold back the dark, fell a single drop of blood. So the shield weakened, and the dark, spider-patient, waited as the decades passed, and the wound spread under the grass and ground.' The brilliant conclusion to the Chronicles of the One trilogy - an epic story of love, war, family and magic. Fallon Swift has spent all her life preparing for this moment. No longer can she stand by whilst her fellow Magicks are hunted by the fanatical Purity Warriors or rounded up and experimented on by the government. Fallon must follow her destiny to restore the magical shield that once protected them all. But she can't do it alone. It is time to build her army, to take on her nemesis and take down the enemy. She has learned to fight, now she must restore the light and banish the dark forever. The final battle has begun...