Rosalie Lapointe loves to tinker. She loves it so much that she occasionally forgets to eat.

She finds it easier to occupy her mind with blueprints and spanner sizes than the deep, agonizing pain of losing her mother many years ago. Her father indulges her hobbies even as he works to find her a mate who will care for her when she cannot care for herself.

When she refuses all of his suitors, Mr Lapointe hires a new manservant as a last resort. But Rosalie's hobby may be more dangerous than she realised; as she tries to work out the kinks in her new steam engine prototype, she discovers that poisonous carbon monoxide may not the biggest threat to her safety.

The distractingly handsome new manservant, Edmund Price, is not helping matters.