The Warlock (Book 5) by Michael Scott
The Newman twins have finally been divided. The end is near.
In San Francisco, Josh has chosen a side – and he will not stand with his sister, Sophie, or the Alchemyst, Nicholas Flamel. He has chosen to fight along side John Dee and the mysterious Virginia Dare. Sophie will do anything she can to find her brother, but her training must continue. With Perenelle and Nicholas as weak as they are, Niten must help her to master Earth Magic. Without this, she will fail and the human race will be doomed forever…
Can she save the world alone?