When World War II spies brainstormed ways to defeat the enemy, they came up with ideas so bizarre—glowing foxes, hormone-laced food, and cat bombs—you’d think they were writing a slapstick comedy instead of a war plan.

When World War II spies brainstormed ways to defeat the enemy, they came up with ideas so bizarre—glowing foxes, hormone-laced food, and cat bombs—you’d think they were writing a slapstick comedy instead of a war plan.