I loved The Doomsday Vault, the first book of the Clockwork Empire, it was such an entertaining steampunk novel, so I can't wait to get my hands on The Impossible Cube!
Spoilers in the summary below if you haven't read The Doomsday Vault!
THE THRILLING STEAMPUNK SERIES CONTINUES...
Declared enemies of the Crown, Alice Michaels and Gavin Ennock have little choice but to flee in search of a cure for the clockwork plague ravaging Gavin's mind. Accompanying them is Dr. Clef, a mad genius driven to find the greatest and most destructive force the world has ever seen:The Impossible Cube. If Dr. Clef gets his hands on it, the entire universe will face extinction.