Adam, appalled, drew his wife to him and held her close.  As far as he could estimate by the interval between lightning and thunder-clap, the heart of the storm was still some distance off, so he felt no present concern for their safety.  Still, it was apparent that the course of the storm was moving swiftly in their direction.  The lightning flashes came faster and faster and closer together; the thunder-roll was almost continuous, not stopping for a moment—­a new crash beginning before the old one had ceased.  Adam kept looking up in the direction where the kite strained and struggled at its detaining cord, but, of course, the dull evening light prevented any distinct scrutiny.

At length there came a flash so appallingly bright that in its glare Nature seemed to be standing still.  So long did it last, that there was time to distinguish its configuration.  It seemed like a mighty tree inverted, pendent from the sky.  The whole country around within the angle of vision was lit up till it seemed to glow.  Then a broad ribbon of fire seemed to drop on to the tower of Castra Regis just as the thunder crashed.  By the glare, Adam could see the tower shake and tremble, and finally fall to pieces like a house of cards.  The passing of the lightning left the sky again dark, but a blue flame fell downward from the tower, and, with inconceivable rapidity, running along the ground in the direction of Diana’s Grove, reached the dark silent house, which in the instant burst into flame at a hundred different points.

At the same moment there rose from the house a rending, crashing sound of woodwork, broken or thrown about, mixed with a quick scream so appalling that Adam, stout of heart as he undoubtedly was, felt his blood turn into ice.  Instinctively, despite the danger and their consciousness of it, husband and wife took hands and listened, trembling.  Something was going on close to them, mysterious, terrible, deadly!  The shrieks continued, though less sharp in sound, as though muffled.  In the midst of them was a terrific explosion, seemingly from deep in the earth.

The flames from Castra Regis and from Diana’s Grove made all around almost as light as day, and now that the lightning had ceased to flash, their eyes, unblinded, were able to judge both perspective and detail.  The heat of the burning house caused the iron doors to warp and collapse.  Seemingly of their own accord, they fell open, and exposed the interior.  The Saltons could now look through to the room beyond, where the well-hole yawned, a deep narrow circular chasm.  From this the agonised shrieks were rising, growing ever more terrible with each second that passed.