They will find out she has taken over, and now is the strongest. Looking forward to them meeting up, I hope he can put up a fight as his friend is a bit tyrannical
We have situations like that ourselves. Ever heard of antibiotic resistant strains of illnesses? It could be like that. It's probably a bit more realistic if their amazing medical technology just ended up causing certain things to become even harder to treat, or brought out entirely new forms of illness. Life is fuckin' messy.