Wayne Kyle Spitzer 
Every Blade of Grass [EPUB ebook] 
An Existential Parable

Three futuristic landscapers battle nature, fatigue, and each other on a terraformed Mars …
The medical rocket is wasted—its consoles smashed, its stores emptied—to the extent that we have collapsed outside its open hatch in total exhaustion and despair. Worse, the air is filled with the roar of machinery—a roar with a band-saw edge—one we know all too well for it is the sound of Cap’s Big Track coming closer every second.
And then he has arrived, riding his tractor like a chariot, goading it forward into the clearing, motoring directly toward us until Taylor jumps up in a panic and sprints for the next bridge—his dark skin shining, his heels kicking up sod—as the Captain veers toward him suddenly and seems to gun the engine.
And then I am running, shouting at him to stop, as Taylor vanishes beneath the blades and the Big Track jounces, once, twice, the Captain laughing and throwing back his head, the iron tracks seeming to catch—until blood begins spewing like grass clippings from the mulch-vents and all I can hear is my friend screaming—gargling—dying beneath the Cap’s iron beast.