The Chronopticus Chronicles Series

Kyrk is on a mission to hit a Martian transport train loaded with precious metals. His new sidekick, Goldman, has other designs. When they both find their plans disrupted, Kyrk finds his new purpose may involve the people fleeing the settlements near the mines of Mars.

This story begins the series, a box set including The Mines of Mars (short story), Fractal Standard Time (short story collection), Ionotatron (novel), and Chronopticus Rising (novel).