But as she went on, and Mr.MacNairn joined in the talk, their meaning became a clear thing to me, and I knew that they were only talking quite simply of something they had often talked of before.

They were not as afraid of The Fear as most people are, because they had thought of and reasoned about it so much, and always calmly and with clear and open minds.
By The Fear they meant that mysterious horror most people feel at the thought of passing out of the world they know into the one they don't know at all.
How quiet, how still it was inside the walls of the old garden, as we three sat under the boughs and talked about it! And what sweet night scents of leaves and sleeping flowers were in every breath we drew! And how one's heart moved and lifted when the nightingale broke out again! "If one had seen or heard one little thing, if one's mortal being could catch one glimpse of light in the dark," Mrs.MacNairn's low voice said out of the shadow near me, "The Fear would be gone forever." "Perhaps the whole mystery is as simple as this," said her son's voice "as simple as this: that as there are tones of music too fine to be registered by the human ear, so there may be vibrations of light not to be seen by the human eye; form and color as well as sounds; just beyond earthly perception, and yet as real as ourselves, as formed as ourselves, only existing in that other dimension." There was an intenseness which was almost a note of anguish in Mrs.
MacNairn's answer, even though her voice was very low.

I involuntarily turned my head to look at her, though of course it was too dark to see her face.

I felt somehow as if her hands were wrung together in her lap.
"Oh!" she said, "if one only had some shadow of a proof that the mystery is only that WE cannot see, that WE cannot hear, though they are really quite near us, with us--the ones who seem to have gone away and whom we feel we cannot live without.

If once we could be sure! There would be no Fear--there would be none!" "Dearest"-- he often called her "Dearest," and his voice had a wonderful sound in the darkness; it was caress and strength, and it seemed to speak to her of things they knew which I did not--"we have vowed to each other that we WILL believe there is no reason for The Fear.