Krells never set out to be a hero. He was the first to admit he was a trader. "In it for the money; I leave thinking to the experts." But the experts couldn't solve the problem of Ralcor IX.
Professional fighters and scientific investigators vanished or were mysteriously destroyed. The robot might of an armoured Bellicose 35 was found shredded like tinsel. Krells still refused to think of himself as hero material - but he wouldn't quit. Martia, his computer girl, and Galor, the despatch man, stayed with him. For some reason the power that had driven every other terrestrial humanoid off Ralcor IX couldn't dislodge the traders. Krells groped desperately for a reason. Finding one meant the return of his own people and that meant money. Something he couldn't understand was shielding him from the Unknown Menace. Suppose he accidentally stopped doing whatever it was that protected him...?
Most people would have become neurotic and quit - not Krells. He didn't seem to have enough intelligence or imagination to know when to worry.
