Endings: be true to yourself
Starting with the ending can generate a wealth of ideas and events. Different types of endings need different kinds of set-up - a grand finalé needs very careful plotting and timing towards the end, a twist needs enough subtle foreshadowing so it doesn’t read as cheating, and so forth.
If you're already writing with these prompts, use what you've developed of your story so far. If you're just starting here, use this premise, Why did the protagonist fake those maps?
Think about these different types of endings. Which do you prefer reading? Which do you think might suit your story / this premise? Choose the kind of ending that you believe in and want to write.
• bittersweet (eg The Time Travellor's Wife)
• grand finalé (eg the Harry Potter showdown)
• morally complex endings (eg Ender's Game)
• twist-in-the-tale (eg Fight Club)
• drawn-out endings (eg The Lord of the Rings)
• over… but is it?! (common with thrillers and horrors: the danger might still be lurking)
• multiple endings / open-ended (eg The Life of Pi, The French Lieutenant's Woman)
Pick a type of ending for the story. What events will constitute that kind of ending? Invent those, then start working backwards - what needs to happen to lead to that ending? If you want to write prose, write the final scene; if you want to story-map, sketch out the events that lead up to the ending.
The twelve days of writing are complete! If you missed any of the prompts and want to try them, you can see all the prompts here. You can do them in any order, building on each other or as stand-alone activities.