I'm having a bit of a dry spell so I figured it would be useful to have a place for brainstorming potential scenario ideas.
AND HERE IT IS.
Some unknown agent turns up, claiming to be from the future, demanding some wierd action be taken to keep the timeline in place. Whether he is actually from the future or working for an outer group, up to you.
Or, UIU stumbles on some big foundation secret. We have to go take care of the secret and keep the UIU shushed up about this.
Anything involving birds with teeth.
Sorry my suggestions aren't very complete.