It was a post of such danger that the officers at Fort Edward, having called for volunteers repeatedly, all of whom had met the same mysterious fate, were compelled to resort to drafting the men for duty there.

As a commissioned officer Putnam was exempt from the draft, but with his love of danger and from a desire to penetrate the mystery, he volunteered for the hazardous service for at least one night.

His offer was accepted, although his friends warned him of the risk he ran.

He was already informed as to the general instructions: on hearing the least noise to challenge promptly, "Who goes there ?" three times, and then, if no answer were returned, to fire at whatever approached.
Mounting guard at his post as early as possible, Putnam took occasion to make a thorough examination of the nature of his environment, with a trained woodsman's eye noting every peculiarity of rock, stump, bush, tree, and leaf.

Even then, as darkness fell and the scene became faintly illumined by the rising moon, his surroundings assumed an unfamiliar cast.
He stood at his post till past midnight before anything unusual happened, then his attention was attracted by what appeared to him a wild hog which, with stealthy footstep, gradually neared his position.
There could be no danger in such a beast, any one less acute than he might have reasoned; but anyway, he issued the challenge, and then, no response having been made to his "Who goes there ?" he immediately fired at the animal.