Retrograde

Venturing into space and travelling to Mars sounds like an exotic adventure, but the reality is living in lava caves hundreds of feet below the surface of a rocky, frozen, lifeless planet is exacting on the Mars Endeavour crew. The only viable option for long term habitation lies beneath the surface of the planet, where humans can be shielded from harsh cosmic radiation.

Connor, Harrison, and Liz are senior members of the US module. When war breaks out on Earth, and rumors begin spreading on...