Join Marrill and Fin in the fourth action-packed title in the epic adventure series from John Parke Davis and NEW YORK TIMES bestselling author, Carrie Ryan.Best friends and fearless explorers Fin and Marrill have shared countless thrilling adventures on the waters of the Pirate Stream, but neither could have predicted the evil that lies behind the mask of the Master of the Iron Ship.To stop him, they'll have to team up with their oldest enemy: the malevolent wizard Serth. As the iron tide surges across the Stream, Marrill and Fin must race from one bizarre world to the next, and even into the heart of the Stream itself, to challenge the most frightening foe they've ever encountered.This is the mind-blowing conclusion to the highly acclaimed and utterly original Map to Everywhere series.