Back to (not) normal life

Carmen Sandiego finally completed her mission. She finally took down V.I.L.E and now all of the faculty members and most of their operatives are arrested.

But what happens when two assassins try to take out both Carmen Sandiego and Graham Calloway?
Who are these people? What do they want?

And most importantly who are the four spies that saved them? If they don't work for A.C.M.E, then who do they work for?