Seventeen Uses for a Locked Door

The numbering here is the form. Read them in order; the list is doing something the sentences are not.

1. To keep a thing in.
2. To keep a thing out.
3. To make a room into a decision.
4. To give a child somewhere to be furious.
5. To prove that the key exists.
6. To prove that the key is elsewhere.
7. To hold the last arrangement of someone's belongings exactly as they left it, which is not preservation but a form of argument.
8. To make a corridor honest.
9. To turn waiting into a profession.
10. To let a house have a secret without anyone having to keep it.
11. To rehearse loss at a manageable scale.
12. To be the reason the story cannot end here.
13. To be knocked on.
14. To be knocked on twice.
15. To become, after long enough, simply a wall with a handle.
16. To be opened by someone who does not know what it cost to close.
17. To be opened.