Nobody answered him.  White had sat down at the instrument table, and was tapping out messages like a man well accustomed to the work.

“Of course with those black mask things over your faces I couldn’t recognize you again, even if I was put in the box; but, my good chaps, your steamer’s known, there’s no getting over that.  Much better clear out before any mischief’s done, and own up you’ve made a mistake.”

White turned on the man with a sudden fury.  “If you don’t keep your silly mouth shut, I’ll have you throttled,” he threatened, and after that the only noise that broke the silence was the tap—­taptap—­taptapping of the telegraph instrument.

Only two men in that darkened room knew what message was being dispatched, and these were White and the dispossessed operator.  The one worked with cool, steady industry, and the other listened with strained intentness.  Sheriff was outside the door keeping guard on the rest of the house.  But Kettle, from his station behind the operator’s chair, listened with a strange disquietude.  He had been told that the object of the raid was to arrange a stock exchange robbery, and to this he had tacitly agreed.  According to his narrow creed (as gathered from the South Shields chapel) none but rogues and thieves dealt in stocks and shares, and if these chose to rob one another, an honest man might well look on non-interferent.  But what guarantee had he that this robbery was not planned to draw plunder from the outside public as well?  The pledged word of Mr. White.  And that was worth?  He smiled disdainfully when he thought of the slenderness of its value.

Tap—­taptap—­tap—­tap—­taptap, said the tantalizing instrument, going steadily on with its hidden speech.

The stifling heat of the room seemed to get more oppressive.  The mystery of the thing beat against Kettle’s brain.

Of course he could not read the deposed operator’s thoughts, though he could see easily that the man was reading the messages which White was so glibly sending off.  But it was clear that the man’s agitation was growing; growing, too, out of all proportion to the coolness he had shown when his room was first invaded.  At last an exclamation was forced from him, almost, as it seemed, involuntarily.  “Oh, you ghastly scoundrel,” he murmured, and on that Kettle spoke.  He could not stand the mystery any longer.

“Tell me,” he said, “exactly what message that man’s sending.”

“But I forbid you to do any such thing,” said White, and reached for his revolver.  But before his fingers touched it, he looked up and saw Kettle’s weapon covering him.

“You put that down,” came the crisp order, and White obeyed it nervously enough.

“And now go and stand in the middle of the room till I give you leave to shift.”

White did this also.  He grasped the fact that Captain Kettle was not in a mood to be trifled with.