“Yeah, I know, i told ya I get them mixed up, what is the name of the agency that covers terrorism within their country?”
MI5, as USF said.
Just for your info, there were once MI1, MI2, MI3, etc, but most were shut down or integrated into the two that remain: MI5 and MI6.
*goes and checks* MI4 apparently was the Aerial Reconnaissance unit :o)
bump for later. I have some chores I have to get done today. Everyone stay safe out there.