2. At A Certain Age, Son, Your Body Goes Through Changes
Most teenagers have to go through their voice cracking, hair in new places, and a sudden interest in all things sexual. William, at least in Scully's dream/visions, has to go through something much more unsettling: Becoming, apparently, alien in appearance. The William question is going to be a big part of The X-Files mythology moving forward it seems. A good chunk of Founder's Mutation was dedicated to the absent son of Mulder and Scully, and there's a good bet that will continue, as giving him up for adoption may have, in the end, been what ended their relationship. Concern for him, however, may bring them back together - and drive them to find him.