Her Majesty's Auditor

When auditing becomes life-threatening ...
Tasked with auditing the accounts of the Queen's ore mines, auditor Howard Forsyth encounters the notorious and feared administrator of the mines. Soon his life is threatened on an adventurous train ride with steam cars and a steam-powered flying object.
This is not how he had imagined Lord Palmerston's audit engagement.
Then, when he is suspected of murdering the former accountant, his secret lover, whom no one is supposed to know about, rushes to his aid.
Will they both survive? What role does the missing general ledger play? What is the sinister invention for?
Not everyone is what they seem.