Thornton in particular? The reasons were forthcoming,
logical and in order: he was a man whom Pollard hated; already Pollard
regretted having sold the Poison Hole ranch for twenty thousand dollars;
he wanted it back; Thornton happened to be a new man in the country and
new men are always open to suspicion; he happened to be close enough to
Ben Broderick in size and form and carriage to make the deception easy.
And, thought Thornton, there was one other reason:

The undertaking of these men had already grown too big, the work too
extensive, for it to be handled by two men alone. They had confederates;
that was inevitable. Blackie, the saloon keeper in Dry Town, was one of
them, he felt sure. The Bedloe boys, always ready for deeds of wildness
and lawlessness, were others. The Bedloe boys hated him as keenly as did
Pollard, and they were not the kind to miss an opportunity like this to
"break even" with him. It was noteworthy that he had had no trouble with
them since he had shot the Kid's revolvers out of his hands at John
Smith's place last winter; they had left him entirely unmolested; the
three of them who he knew were fearless and hard and vengeful, had not
sought in any way to punish him. Here was the reason.

He went back to Winifred Waverly's letter. She had ended by saying,

"I know that Henry Pollard suspects me of knowing more than I have
admitted to him; I suppose I did not entirely deceive him about that
yellow envelope. He is watching me all the time. That is why I have
written this to be ready to give it to you if I get the chance, if I
dare not talk with you. Don't try to see me. I am in no danger now, but
if you came, if he knew that we were seeing each other.... I don't
know."

At last when Thornton got up and went to his door day was breaking. He
returned to his table where his lamplight was growing a sickly, pale
yellow in the dawn, and holding Winifred's letter over the chimney
burned it. He took her other little note from his pocket and let the
yellow flame lick it up. Then, grinding the ashes under his heel, he put
out the light and went again to the door.

The recent shooting at the Here's How Saloon by some man who had stood
almost at the cowboy's elbow, he had for a little forgotten as he
pondered on his own personal danger and admitted that the case was going
to look bad against him in spite of what he might do. But now, for a
moment, he forgot his own predicament to become lost in frowning