<P><I>A crossroads can be a place of great power.</I> So begins this deliciously spine-tingling prequel to Kate Milford’s <I>The Boneshaker,</I> set in the colorful world of nineteenth-century Coney Island and New York City. Few crossroads compare to the one being formed by the Brooklyn Bridge and the East River, and as the bridge’s construction progresses, forces of unimaginable evil seek to bend that power to their advantage. Only two orphans with unusual skills stand in their way. Can the teenagers Sam, a card sharp, and Jin, a fireworks expert, stop them before it’s too late? Here is a richly textured, slow-burning thriller about friendship, courage, and the age-old fight between good and evil.