It's a free event, just go to the region he's at, should be the second one towards the bottom of the left-most ones on the overview map I believe meaning it's one of those with the fir trees and what not and then when nearby a mission icon should pop up. (Some mangrove swamp area, a civilian nearby will give the mission to the team.)
Assuming the event is still ongoing of course, if it's online only and with a timed expiration then there's not much to be done about it.
Fallen Ghosts the little epilogue bit to the game is a paid DLC though as is that other one serving as some side story.
EDIT: And then you can use the table because the AI partners don't know how to duck the big incoming beam attacks and worse.
(Tier-1 sniper rifle and a dozens shots if not more, thing takes down armor in one shot so he's kinda tanky.)
EDIT: Hmm another update, this must be the Splinter Cell tie-in then I'm guessing and what the next title update will do for the game in general.
EDIT:
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