While the first add-on Blood of Sahara played after Bet on Soldier: Blood Sport, Black-out Saigon takes place ten years before it. The Syndicate still is the main power on the world and controls nearly everything. But the WRF is gaining strength and the VAN still has the control over most of Asia. You now play as Hang Shaiming, an elite soldier of VAN who has been send to Saigon on a reconnaissance mission only to find out that the WRF already has begun their assault on Saigon.
The add-on has four new missions in which Hang fights his way through enemy lines in and around Saigon while discovering that the Syndicate has it's hand in the whole thing, too. There are also eight new B.o.S champions in your way, which you need to take down with the help of your huge weapon arsenal. Black-out Saigon adds two new weapons to the already known weaponry: the Intensive Care which is a very powerful rocket launcher that only has one shot and the Nixen which is the standard assault rifle of the VAN-forces.