Cristabel and her younger siblings, Flossy and Digby spend their youth telling stories and putting on productions using the bare skeleton of a whale as their theater.
The acting skills they gained in their youth come in handy for Cristabel and Digby when they become spies for the British in France during WWII.
It felt like two entirely different books. For me, the first half when they were kids dragged but the second half during the war was great.