Secret of the Martians

Few colonists had seen a Martian, so why worry about them causing trouble? Yet Spencer had been killed—and Rex Tate trapped by the—
Gordon Malloy, Chief of Interplanetary Security, rocked back in his chair, and with seeming unconcern looked Rex Tate over searchingly. How was Pluto?
Stinking. Why we want that frozen lump in the Federation is something I can't figure.
Rich in minerals.
You left me there for seven Terran months, Rex allowed criticism to sound in his voice.
This did not bother Malloy. Good for you. Toughened you up. Safe too. Never much trouble on Pluto.
That's why I joined up. So I'd be nice and safe.
I've got something in mind for you.
Where?
Mars. But it could be nasty so you'd better go back to Pluto.
Try and get me on a ship. What's with Mars?
Malloy looked for a place to put his feet and found only the top of his desk. Up there they looked like a pair of crossed banjo cases.