A series of similar words followed, and as the experiment took this new direction David’s nervousness vanished. Then, without warning, the travel series was taken up again; and this time each word came like the blow of a hammer upon a nail that is swiftly and surely driven to its mark.

There was no mistaking the result. David’s limbs stiffened, as if to ward off a blow. His look of relief gave place to a hopeless sort of misery; the telltale electric finger jumped forward in exaggerated lines as if to escape from some merciless pursuer.

“South America,” demanded Leighton.

“Spaniards,” after a pause, was David’s answering word.

“Mountains.”

“Muleback.”

“Lake.”

“Gold.”

The answers were hesitatingly given, almost inaudible. Again Una protested.