scullaaay:

September 2012. Mulder is warned that his son life is in danger. Aware of these news and the imminent alien invasion, he and Scully go after William. When they arrive at his adoptive parents’ farm, the Van De Kamps are already dead but William managed to escape. They take William with them to protect and hide him from the aliens. But the boy is having trouble dealing with his new world and his new-found biological parents. 

The X-Files: End of Days