Cogheart (Standard format, CD, Unabridged edition)

When thirteen-year-old Lily's inventor father vanishes on a routine Zeppelin flight, Lily's determined to find out the truth behind his disappearance. But she's not the only one searching for her father; there are silver-eyed men in the shadows who will stop at nothing to find him. With Robert, the local clockmaker's son, Lily travels to London, where they soon discover that she holds the key to the mystery...a mystery closer to Lily's heart than she could have ever imagined.