I love the name Savannah. We almost named my daughter that. And yes! Sci fi would be cool, like spy sci if with brainwashing and stuff. Is that what you are leaning towards?
This sounds interesting, are you going add in sci-fi elements to explain what happen to Savannah during her disappearance? Has a sci-fi feel to it! :D Good job on the summary, for sure caught my attention! Can't wait to take a look at it next month.