The hook starts it. Someone behind it wants something, and what is at stake is what the players stand to lose. The twist is what you hold back until the middle. Keep what fits your game and roll the rest; Copy puts the plotline on your clipboard.
An ALRP author can open the book with the hook and save the twist for a later post. When the players send in answers too good to choose between, the timeline can split and they vote (Split the Timeline).