And Then There Were 65: The Secret Adversary by Agatha Christie

Time for Dame Agatha's very first thriller featuring the delightful
detective duo Tommy & Tuppence taking on the devious criminal
mastermind "Mr. Brown." Was Tuppence modeled at least somewhat on
young Agatha herself? Is "hanging a lantern" an appropriate
technique to use in a novel? Do American teenagers really know
French *that* well? All these answers... and more!