“I suggest,” said Martin calmly, “that your position when von Faber discovered that your prisoner had ‘eluded your vigilance,’ as you call it, would not have been too good.”
Whitby paused thoughtfully.
“Not bad,” he said. “Not bad at all. Very pretty. But”—he shook his head—“unfortunately not true. My position with Coombe dead was ‘not good’ as you call it. But had Coombe been alive he would have had to face the music, wouldn’t he? It was von Faber’s own fault that I ever left his side at all.”
This was certainly a point which they had not considered. It silenced them for a moment, and in the lull a sound which had been gradually forcing itself upon their attention for the last few moments became suddenly very apparent—the steady droning of an aeroplane engine.
Whitby looked up, mild interest on his face.
It was now quite light, and the others, following his gaze, saw a huge Fokker monoplane flying low against the grey sky.
“He’s out early,” remarked Prenderby.
“Yes,” said Whitby. “There’s an aerodrome a couple of miles across here, you know. Quite near my house, in fact.”
Martin pricked up his ears.
“Your house?” he echoed.
The little doctor nodded.
“Yes. I have a small place down here by the sea. Very lonely, you know, but I thought it suited my purpose very well just now. Frankly, I didn’t like the idea of your following me and it made my friend quite angry.”
“Hullo! He’s in difficulties or something.”
It was Prenderby who spoke. He had been watching the aeroplane, which was now almost directly above their heads. His excited cry made them all look up again, to see the great plane circling into the wind.
There was now no drone of the engine but they could hear the sough of the air through the wires, and for a moment it seemed as if it were dropping directly on top of them. The next instant it passed so near that they almost felt its draught upon their faces. Then it taxied along the ground, coming to a halt in the glow of the still burning headlights of the big car.
Instinctively, they hurried towards it, and until they were within twenty yards they did not realize that Whitby’s confederate had got there first and was talking excitedly to the pilot.
“Good God!” said Martin suddenly stopping dead in his tracks. The same thought struck the others at precisely the same instant.
Through the waves of mingled anger and amazement which overwhelmed them, Whitby’s precise little voice came clearly.
“I observe that he carries a machine-gun,” he remarked. “That’s what I like about these Germans—so efficient. In view of what my excitable colleague has probably said to the pilot, I really don’t think I should come any nearer. Perhaps you would turn off your headlights when you go back, they have served their purpose. Take the car too if you like.”
He paused and beamed on them.
“Goodbye,” he said. “I suppose it would annoy you if I thanked you for coming to see me off? Don’t do that,” he added sharply, as Martin’s hand shot to his side pocket. “Please don’t do that,” he repeated more earnestly. “For my friends would most certainly kill you without the least compunction, and I don’t want that. Believe me, my dear young people, whatever your theories may be, I am no murderer. I am leaving the country in this melodramatic fashion because it obviates the inconveniences which might arise if I showed my passport here just at present. Don’t come any nearer. Goodbye, gentlemen.”
As they watched him go, Martin’s hand again stole to his pocket.
Abbershaw touched his arm.
“Don’t be a fool, old man,” he said. “If he’s done one murder, don’t encourage him to do another, and if he hasn’t, why help him to?”
Martin nodded and made a remark which did nobody any credit.
They stood there watching the machine with the gun trained upon them from its cockpit until it began to move again; then they turned back towards the Riley.
“Right up the garden,” said Martin bitterly. “Fooled, done brown, put it how you like. There goes Coombe’s murderer and here are we poor mutts who listened trustingly while he told us fairy stories to pass the time away until his pals turned up for him. I wish we’d risked that machine-gun.”
Prenderby nodded gloomily.
“I feel sick,” he said. “We spotted him and then he got away with it.”
Abbershaw shook his head.
“He got away certainly,” he said. “But I don’t think we’ve got much cause to regret it.”
“What do you mean? Think he didn’t kill him?”
They looked at him incredulously.
Abbershaw nodded.
“I know he didn’t kill him,” he said quietly.
Martin grunted.
“I’m afraid I can’t agree with you there,” he said. “Gosh! I’ll never forgive myself for being such a fool!”
Prenderby was inclined to agree with him, but Abbershaw stuck to his own opinion, and the expression on his face as they drove silently back to Town was very serious and, somehow, afraid.
XXIX
The Last Chapter
In the six weeks which followed the unsatisfactory trip to the Essex Marshes, Abbershaw and Meggie were fully occupied preparing for their wedding, which they had decided should take place as soon as was possible.
Prenderby seemed inclined to forget the Black Dudley affair altogether: his own marriage to Jeanne was not far distant and provided him with a more interesting topic of thought and conversation, and Martin Watt had gone back to his old haunts in the City and the West End.
Wyatt was in his flat overlooking St. James’s, apparently immersed as ever in the obscurities of his reading.
But Abbershaw had not forgotten Colonel Coombe.
He had not put the whole matter before his friend, Inspector Deadwood of Scotland Yard, for a reason which he was unable to express in definite words, even to himself.
An idea was forming in his mind—an idea which he shrank from and yet could
