But years before 007 first wielded a laser watch or an exploding pen, Britain’s top spies were being kitted out with tech that might have left Ian Fleming’s fictional hero stunned. They included booby-trapped soy bottles that blew up when opened by chefs on Japanese supply ships, exploding rats used to destroy German factories and detonators stashed in tubes of toothpaste. The lethal gadgets of the real-life Q Branch, dubbed the Camouflage Section, have been described in a new book by historian Craig Moore. “James Bond has Q Branch to supply him with ingenious equipment to use on his missions,”...