The Secret Tomb

When Dorothy, ropedancer and palmist, arrives at the Château de Roborey with her circus, she's already observed strange excavations at the grounds. Fate reveals a familial connection and drags her and her motley crew of war orphans into a quest for long-lost ancestral treasure, but her new-found nemesis is always close on her trail. Maurice Leblanc, most famous for his Arsène Lupin stories, here switches to a new protagonist, but fans of his other work will find her strangely recognisable.
Indeed, the mystery presented here is later referenced in The Countess of Cagliostro as a puzzle that Lupin did not have time to solve. This book was originally serialised in Le Journal between January and March 1923, and was published in novel form both in French and in this English translation later in the year. It was also later adapted as a French-language made-for-TV movie in 1983.