02 - Beast-Jewel of Mars by Leigh Douglass Brackett

After the mysterious death of his girlfriend, Captain Burk Winters embarks on a perilous journey through the treacherous world of Martian vice known as Shanga‚Aîthe Going Back. What begins as a desperate mission to save Jill Leeland soon spirals into a confrontation with the sinister underbelly of the canal cities, fraught with conspiracies fueled by greed. As Burk fights to uncover the truth, he must also contend with the fierce vengeance of a planet refusing to submit to economic domination. - Summary by EVKesserich