Lunar Dust, Martian Sands

Ed Ferald, pilot of the tug Cydonia Zach on the Martian-Lunar run, receives orders from his uncle and boss to take an enigmatic woman as his sole passenger on the return to Mars. But he doesn't have much time to find out much about her as soon finds himself plunged into disasters on the Red Planet and off, and ensnared in plots fed by Earth politics and corporations fighting to preserve their profits, even if it means putting the survival of the Martian colony at risk.

Ed's passenger is at the center of the fight, though on what side he can't tell. He only knows he has to uncover the plot's conspirators to preserve his Martian home - and to keep from being the next one killed.
Lunar Dust, Martian Sands is the first book of the Martian Sands series, set in the early years of the 22nd century. The science is plausible, but the techonolgy is kept mostly in the background. At the forefront are the people trying to earn a living and carve out a future in the domed cities surrounded by a barren landscape. The story is a science fiction thriller, punctuated by sharp repartee that inserts humor to break the tension for the characters and the readers.
But there's always another corner to turn, and another secret to uncover.