United States Marshal Preston Flynn, the mysterious young man who became a deputy marshal at age sixteen, displays his power of concentration and awesome physical strength that exceeds the bounds of human ability, defying the impossible.

He agrees to help the small ranchers fight for survival against the cutthroat cattle buyers, being instrumental in forming a union that guarantees its members fair prices for their beef.

The union president is shot and killed. The evidence of Flynn's investigation leads to Ben Sharp, a drifter. However, Judge Vanrail, jealous of Flynn's youth, ability, and reputation, claims his evidence is circumstantial, and orders Flynn to turn Sharp loose. The crimes against the union members continue. Flynn confronts Vanrail in anger, and

Vanrail finds him in contempt, fines him, and strips him of his badge. He has no alternative but to move around the judge, if he is to protect the union members, forced to stop Sharp the only way left to him. Flynn ends up behind bars, facing a rope, and helpless when five outlaws decide to take over the town.

For the first time Flynn begins to understand his unique power of concentration, and the mystery of his superhuman strength.

The mystery of his parent's murder, (Book I) that he witnessed at age six, is finally solved, answering the question that has plagued him most of his life.