Yet the red borders of that accursed land, the bloody altars of which were served by the priests of Baal, lay but a few scant kilometres to the north and east.  And their stealthy emissaries were over the border and creeping like vermin among the uncontaminated fields of France.

“Even here,” Recklow was saying, in a voice made low and cautious from habit, “the dirty Boche prowl among us under protean aspects.  One can never tell, never trust anybody—­what with one thing and another and the Alsatian border so close—­and those German-Swiss—­always to be suspected and often impossible to distinguish—­with their pig-eyes and bushy flat-backed heads—­from the genuine Boche. ...  Would Miss Erith like to have our little dinner served out here in the garden?”

Miss Erith was delightfully sure she would.

It was long after sunset, though still light, when the simple little meal ended; but they lingered over their coffee and cordial, exchanging ideas concerning preparations for their departure, which was now close at hand.

The lilac bloom faded from mountain and woodland; already meadow and pasture lay veiled under the thickening dusk.  The last day-bird had piped its sleepy “lights out”; bats were flying high.  When the moon rose the first nightingale acclaimed the pallid lustre that fell in silver pools on walk and wall; and every flower sent forth its scented greeting.

Kay McKay and Evelyn Erith had been gone for nearly an hour; but Recklow still sat there at the little green table, an unlighted cigarette in his muscular fingers, his head slightly bent as though listening.

Once he rose as though on some impulse, went into the house, took a roll of fine wire, a small cowbell, a heavy pair of wire clippers and a pocket torch from his desk and pocketed them.  A pair of automatic handcuffs he also took, and a dozen clips to fit the brace of pistols strapped under his armpits.

Then he returned to the garden; and for a long while he sat there, unstirring, just where the wall’s shadow lay clean-cut across the grass, listening to the distant tinkle of cattle-bells on the unseen slope of Mount Terrible.

No shots had come from the patrol along the Franco-Swiss frontier; there was no sound save the ecstatic tumult of the nightingale drunk with moonlight, and, at intervals, the faint sound of a cowbell from those dark and distant pastures.

To this silent, listening man it seemed certain that his two guests had now safely crossed the boundary at the spot he had marked for McKay on the detail map.  Yet he remained profoundly uneasy.

He waited a few moments longer; heard nothing to alarm him; and then he left the garden, going out by way of the house, and turned to lock the front door behind him.

At that instant his telephone bell rang and he re-entered the house with a sudden premonition—­an odd, unreasonable, but dreadful sort of certainty concerning what he was about to hear.  Picking up the instrument he was thinking all the time:  “It has to do with that damned Intelligence Officer!  There was something wrong with him!”