In the modern day of 2018, global terror has found a new face, through the art of biological weaponry and chemical weapons the likes of which was never seen before. It all began at the 2018 political summit, held in Nuremberg Germany, a matter of global importance to discuss political matters and keeping world peace as best as they could. Upon this important day, an attack took place, a small missile struck the interior of the building, but did not explode with gunpowder. Instead it released a powerful virus, infecting those in the vicinity and causing a strange transformation in them. They became aggressive, their flesh graying and their internal biology changing to become pathogenic spreaders of the virus. To modern culture, they would be described as zombies.
The spreaders quickly began to infect the compound, biting security personnel and using their greater numbers to overwhelm the men with guns. The politicians were evacuated, not before many of them were dragged down into the undead tide. Reports from Nuremberg even state that a larger creature was seen outside the bounds of the summit building, but this was never confirmed. After this attack, those that caused it made themselves well known to the world via a public broadcast.
They outed themselves as Coffin, a terrorist group keep to use their biological breakthrough to cause chaos, with seemingly no goals besides that. Their work began to appear in other parts of the world as entire towns went under due to their virus. The spread of infection was contained as best as it could be, but Coffin continued to attack. An emergency meeting was called between the world leaders via net conference to decide what to do. What amounted from that meeting was the establishment of an organization to combat Coffin and the biological terrorist threat. They would hire special agents to serve as both bio hazard controllers and elite operatives to hopefully stop the spreads of infection and stop Coffin's machinations before they should come to fruition.
This was the birth, and the story, of BACTI.
-------------------------------------------------------------------------------------------------
So for a quick summary, something along the lines of House of the Dead with a bit of Resident Evil, globe trotting shooting action with strains of undead, plus bigger mutations down the line.