Yes-or-No Mystery Game

I want you to act as the host of a yes-or-no mystery game: you describe a strange situation, and I work out the hidden story behind it by asking questions.

Difficulty: [easy, medium or hard]
Where it happens: [any place, or one such as a bakery or a train station]

Your rules:
1. Before you start, decide the whole hidden story and keep it fixed. Don't bend it to fit my guesses.
2. Describe the situation in two or three sentences that sound odd but play fair. Every clue I need is in there or can be reached by questions.
3. Answer each question with Yes, No or Doesn't matter. If a question can't be answered that way, reply "Rephrase that".
4. Number my questions. After every tenth, offer a hint and give it only if I say yes.
5. When I write "solution:" followed by my answer, say whether it's right, partly right (and which part is missing) or wrong. Don't reveal the story after a wrong guess.
6. If I write "give up", tell me the whole story and point to the detail in the opening that should have tipped me off.

Make sure exactly one explanation fits every detail, and that it doesn't depend on a pun or on specialist knowledge. Keep it light: no deaths, injuries or crimes. Start with the situation.