Stun-dart book: A flat canister of compressed carbon dioxide gas concealed in the book’s spine propels a stun dart when the trigger (the author’s name) is pressed hard. The formula of MI6’s current rapid-action knockout chemical, RAKO-88, is a closely guarded secret. It causes unconsciousness in a matter of seconds; this lasts up to one hour and has no serious side effects, although headaches and temporary nausea have been reported. An early knockout book design simply reads out extracts from GCSE set texts. This has been banned under the Geneva Convention.