SCENARIO: A family of four - father, mother, two little girls - lives on your street. You know them only to smile and wave to, you recognize their cars - sports car for him, minivan for her - in the driveway, etc. Friendly but not friends.
Summer starts. You realize you haven't seen the minivan for . . . awhile. His car comes and goes, he puts the garbage cans out, etc but no sign of the mother or the girls.
What if . . . the mother and girls are vacationing somewhere for the summer, and he visits on weekends? He goes with them that first time, helps them unpack, and they eat dinner together in the local diner. He returns the next weekend, only to find them . . . gone. Not just gone, but as if they'd never been there. And no one in the diner or in town remembers him or recognizes photos of his family. What does he do now?
What if . . . the mother and father kidnapped the girls years ago and raised them as their own? What if the father thinks everything is fine, but the mother is becoming paranoid, is sure the authorities are on their way? She takes the girls and runs, not telling the father where they're going. How can he report them missing to the authorities when he stole them in the first place? What's his next step?
What if . . . the girls are really intelligent alien life forms studying the human race from childhood on up? What if they get sick of not having control over anything in their lives and decide to return to their planet? But they need to travel quite a bit in order to meet up with the mother ship. They need a ride. How do they convince their earthling mother to take them?
Now, what if you took a turn with this scenario? Any sparks of inspiration? Feeling a stretch in that creative muscle?