" The beauty of this passage seems to me marred by the awkward yet necessary interruption, "under these circumstances it is," which would have been avoided by opening the sentence with "such evanescent hauntings of our forgotten selves are most apt to startle us in solitudes," &c. Compare the effect of directness in the following:

He agreed at once, especially as I told him I intended to keep the whole business quiet, and try to get to the bottom of the curious affair; for he was anxious to keep the rumor of the haunting from getting about.

With it on either side, moved those other junkssquat, menacing, standing low on the horizon, but as haunting as dark ghosts.

The music filled the air with heavenly harmony, and it set him to vibrating like a tautened string; it rippled forth, softer than the breeze, more haunting than the perfume of the frangipani.