Mirrorworld Book 2: The Magick Earth - Mirrorworld, #2

Companions Netta, Bobby, Raven and Jeanne use Raven's Eidolon to follow the evil wizard Stormwalker to the Magick Earth, where they hope to finally catch him and bring him to justice. However, as soon as they arrive the Earl of De Laney City has them all thrown in gaol for the abduction of his daughter, Jeanne. While the companions are languishing in the earl's fetid prison, Stormwalker butchers the old man and his sons are forced to release Raven and his friends so they can continue their quest.
They enlist the help of a mysterious Elven mage named Giltherion to help track the vile wizard. Then they learn that Stormwalker has fled De Laney City. Raven and his friends are forced to take a perilous sea-journey across the world, all the way to the Magick Earth's New York. While the travellers take advantage of the long journey to learn magic, hone their fighting skills and regain lost fitness, Stormwalker's forgotten past finally starts to catch up with him.
Stormwalker arrives in New York haunted by images from his shattered childhood. He remembers Giltherion and realises he is the key. He captures the Elven wizard to interrogate him, then sends a message to Raven, calling for a final confrontation. However Stormwalker's dark plan is not to fight Raven, but to sacrifice him to the Storm. Also available in this series:Mirrorworld Book1; Eidolon