No one entered.
Expectation was just passing into a vague surprise, when the knocks were repeated—three heavy blows, obviously deliberate, upon the after-wall of the charthouse.
Horst sprang up, with a savage curse of exasperation. He was self-controlled enough, however, to utter his thought in Swedish. “I’ll teach them!” he exclaimed, as he flung open the charthouse door. “Fooling around here!”
He disappeared into the night and they heard the tramp of his heavy sea-boots as he ran round the charthouse. But no other sound woke upon his passage. The circuit completed, they heard his angry yell to the look-out man on the bridge above, heard the quietly normal response, the surprised denial. The interior of the charthouse was a hushed stillness where Jensen and Lyngstrand sat exchanging a smile of malicious enjoyment. Horst vituperated the stammering look-out man in a flood of ugly oaths that were plainly a break-down of nervous control.
The door opened again for his entry.
“Extraordinary thing!” he scowled across at them. “No one there! You heard them, didn’t you?” He seated himself with an angry grunt.
Before they could answer, the knocks recommenced in a sudden vehemence—not slow and deliberate this time, but in a rapid succession which quickened to a fast and furious fusillade from origins that seemed to play, flitting arbitrarily, all over the walls and roof. The charthouse reverberated with them. Their intensity varied at every moment from sharp, hammer-like blows to rapid, nervous taps from what might have been a feverishly agitated pencil. The wild and uncanny tattoo culminated in three crashing blows that seemed to be on the underside of the table itself. There was silence.
“What are you playing at?” cried Horst, glaring at them in fierce suspicion of a hoax.
For answer, they both lifted up their hands, obviously unoccupied, into the air. Even as they did so, the knocks started again, still rapid, but with a certain deliberate rhythm, and much less violent. Again they seemed to be on the underside of the table. Horst looked, with a scowl of distrust, under it to their immobile feet. The two young men glanced at each other, as puzzled and alarmed as Horst himself.
“What in the name of Heaven is it?” cried Jensen.