Again the other answered, this time lifting himself to his full height, sending a message along the nerves of his back that prickled his own skin and passed out along the tail with an exquisite ripple of movement.  And once more came the answer from below.

So the preliminary challenge went on.  Already in the voice of each there had begun to show itself that faint note of hysteria that culminates presently in a scream of anger and a torrent of spits, leading again in their turn to an ominous silence and the first fierce clawing blows at eyes and ears.  In another instant the watcher above would recoil for a moment as the swift rush was made up the trellis, and then the battle would be joined:  but that instant never came.  There fell a sudden silence; and he, peering down into the grey gloom, chin on paws, and tail twitching eighteen inches behind, saw an astonishing sight.  His adversary had broken off in the midst of a long crescendo cry, and was himself crouched flat upon the narrow wall staring now not upwards, but downwards, diagonally, at a certain curtained window eight feet below.

This was all very unusual and contrary to precedent.  A dog, a human hand armed with a missile, a furious minatory face—­these things were not present to account for the breach of etiquette.  Vaguely he perceived this, conscious only of inexplicability; but he himself also ceased, and watched for developments.

Very slowly they came at first.  That crouching body beneath was motionless now; even the tail had ceased to twitch and hung limply behind, dripping over the edge of the narrow wall into the unfathomable pit of the garden; and as the watcher stared, he felt himself some communication of the horror so apparent in the other’s attitude.  Along his own spine, from neck to flank, ran the paralyzing nervous movement; his own tail ceased to move; his own ears drew back instinctively, flattening themselves at the sides of the square strong head.  There was a movement near by, and he turned quick eyes to see the lithe young love of his heart stepping softly into her place beside him.  When he turned again his adversary had vanished.

* * * * *

Yet he still watched.  Still there was no sound from the window at which the other had stared just now:  no oblong of light shone out into the darkness to explain that sudden withdrawal from the fray.

All was as silent as it had been just now; on all sides windows were closed; now and then came a human voice, just a word or two, spoken and answered from one of those pits beneath, and the steady rumble of traffic went on far away across the roofs; but here, in the immediate neighborhood, all was at peace.  He knew well enough the window in question; he had leapt himself upon the sill once and again and seen the foodless waste of floor and carpet and furniture within.