The Sacrifice by Algernon Blackwood

Once in his chilly bedroom he realised that his upper mind had permitted him to do a foolish thing; he had drifted like a schoolboy into an unwise situation. He had pledged himself to an expedition with two strangers, an expedition for which normally he would have chosen his companions with the utmost caution. Moreover, he was guide; they looked to him for safety, while yet it was they who had arranged and planned it. But who were these men with whom he proposed to run grave bodily risks? He knew them as little as they knew him. Whence came, he wondered, the curious idea that this climb was really planned by another who was no one of them?

The thought slipped idly across his mind; going out by one door, it came back, however, quickly by another. He did not think about it more than to note its passage through the disorder that passed with him just then for thinking. Indeed, there was nothing in the whole world for which he cared a single brass farthing. As he undressed for bed, he said to himself: 'I shall be called at one. but why am I going with these two on this wild plan?. And who made the plan?'.