Book 1 in the 1920s detective series starring twin sisters Christie and Agatha! When Agatha accidentally eats a major scientific discovery hidden in a sandwich, it's a race against time for twins Agatha and Christie to find out who's trying to ruin physician Sir Alexander Flemings reputation. About the Christie and Agatha's Detective Agency series: It’s not easy growing up in the 1920s. While Christie can usually be found up a tree or trying a spot of amateur engineering, her shy twin Agatha buries her nose in books and dreams of being a writer. The pair couldn’t be more different. But when a scientific discovery goes missing, they find that together they make a winning combination and Christie and Agatha’s Detective Agency is born. Join the twin detectives as they solve thrilling mysteries all over the world!