Spoiler alert: CPS survives the apocalypse!

I've been watching a BBC series called Survivors on DVD. It's not a reality show, it's a very good remake of a drama from the 1970s. This version hasn't aired in North America yet, so this really is a bit of a spoiler:
The plot deals with what would happen if a virus that appears to be the flu wipes out 99 percent of Earth's population – like that would ever happen. Survivors include a young man and an 11-year-old boy who form a father-son relationship.
In Episode 4, the one surviving bureaucrat in all of Britain decides the father figure is unfit, and tears them apart.