Write a mystery. It can be about anything from who murdered the millionaire to who stole the cookie out of the cookie jar. However, there are a few stipulations.
1) There has to be at least one suspect
2) There has to be a twist
Other than that, you have free rein to do as you please. Enjoy!
Note: The Rating is just so that whatever you create, is still within the bounds of law. Think nothing of it. Or rather, do think something of it, but do not let it bother you overmuch.