The plot of the 1st season (Spoilers) (Hitman (2016))

Explain to me debilu, what is the same, the plot of the game, I don't understand is a sequel, prequel, restart ? Well, with missions more or less clear, but what happens in the video between them ? Some unshaven guy runs using the Agency (and the Agency itself is not aware of his plan) and he wants to reach a world government Providence so what?
He brings some key from some guy, while the other two dudes are pissing themselves that they have the key lost and he gets to Providence. It is possible to open the key ? Shta ? This unshaven man knows 47го and target it from the sniper rifle, but not kill, on the other hand, these Providence in the final video, coming to Diana and say that to blame the 47th, but he was just a mercenary, what's happening here ?