Mars in Carnage

Humanity's dream of colonizing Mars quickly becomes a fight for survival. Mission director Lt Col. John Hathaway sends astronauts Aadya "Kate" Khatun and Hamza "Arti" Artsruni to explore and establish a foothold on the Red Planet. One astronaut is killed, during what appears to be an alien attack; the other makes a solo, dangerous return to a hero's welcome on Earth. Over a century later a Martian colony has firmly established-the underground city of Katarti, Cecil Townley, a tour guide for visitors to Mars is captured by a band of terrorists trying to end what they believe are horrible governmental actions on Mars.
Hiding in underground tunnels, they begin their attack with Townley forced to be their guide. Their actions introduce him to a world he never knew existed, far from the innocent tale he had been telling newcomers for years.