Apocalyptic Red Alert

Because of the G virus... the world has changed. All you can smell is the smoke everywhere, the most you can see is the ubiquitous flames, and the strongest sound you can hear is... the buzzing of the zombie swarm.
Han Feng stood on the top floor of the apartment building, scanning this chaotic world.
Behind him stood a team of solemn Red Alert soldiers.
"I think... if it weren't for them, I might be like everyone else, a low-level zombie with no IQ and only for killing?"
"Report to the commander! The defense system of Base No. 2 has been built! Should it be turned on? Please instruct!" Tanya's voice came from my mind.
"All defense systems are turned on! All research departments speed up the research on the source of the virus! All mobilized soldiers are dispatched! The spy team will block the virus source!"
I want to see who has turned this world into this!