Then he remembered and the whole pattern fell into place. Blue Elk, Benny Grayback, Rowena Ellis, Red Dillon—they had trapped him, every one of them, had tried to run his life, make him do things their way. And now Mary Redmond.

Through the author's description of Tom's thoughts in Chapter 41, it becomes clear why Tom resents Mary and fears her control of him. Because his last, violent ride has so seriously injured him, he feels vulnerable and exposed by his weakness. While Mary has the best intentions for Tom's well being, the circumstances of his past skew his perspective and convince him that she intends to control him rather than help him. Having struggled for years to gain his independence, Tom remains exceedingly wary of once again becoming dependent on another person.