They had been cruising for about five minutes and were well out over the water when Rudd tapped him on the shoulder and jerked a grimy thumb towards their tail.
Gregory looked back towards the coast and saw what it was that had caught Rudd's attention. Dead in their rear certain stars in a long oval patch of sky seemed to be blacked out for a moment and then show up again. It was the smuggler fleet behind them and Gregory cursed himself as a fool for not having realised that the flares were only necessary to guide the planes in to their unofficial landing ground. Directly all the machines had arrived the flares would be put out in order further to shorten the time in which discovery of the secret base was possible by a casual plane passing over.
He began to climb again. His intention being both to gain further altitude and, by the resulting loss of speed, allow the smuggler feet to pass under him. Ten minutes later he was up at five thousand feet and dimly silhouetted below him against the sea stretched the long line of heavy bombers; but now they were climbing too and he judged that they meant to pass over the English coast at as great an altitude as possible, in order to escape drawing attention to themselves by the roar of their engines.
He climbed still higher as they passed beneath him, and altered his course a little when he noted that the fleet was now veering to the north.
Soon he picked up the lights of the English coast lying thousands of feet below to his left and, having acquainted himself with the varying flashes of the Kent lighthouses that morning for just this purpose he was able to check his course as almost dead northward, with Dover and the South Foreland light on his beam.
The smuggler fleet was a good way ahead, below him now and still climbing, but he hoped that if he could maintain his present distance they would lead him in to their English landing ground without suspecting that they were being followed. Unfortunately, visibility ahead was by no means so good as it had been over the French coast, and a moment later they passed through a cold wisp of cloud.
Gregory grabbed the throttle lever in his left hand and pushed it through the gate of the quadrant, bringing his supercharger into play and decreasing his distance a little, as he feared to lose the squadron; but they flew on, still gaining height, and apparently taking advantage of the cloud patches rather than avoiding them. A few moments more and he could see only two machines on the extreme right wing of the flight.
Cursing the clouds, he mounted again, hoping to get above them but the upper layers proved thicker than any he had yet encountered and now the smugglers had disappeared. The Sound of their engines was of no assistance since the roar of his own blacked out any other vibration; and as they were flying without lights he could only hope to spot them again in a clear patch then they momentarily obscured a star here and there.
For another ten minutes he flew on; still towards the north. He could no longer see the coastline below him bat judged that they must have left Deal behind on their left and were coming up to Ramsgate. In the dense cloudy masses through which they were now flying it seemed that all hope of sighting his quarry had vanished, so he decided that his best course was to get down below the cloud banks, pick up the coast, and cruise along it on the off chance that he might spot the smugglers when they came down towards their secret landing place. He had little hope that luck would favour him as it was probable that each machine would make for a separate destination, perhaps far inland, but it was worth trying.
Five minutes later he was free of the clouds and picked up Ramsgate with the North Foreland light beyond it. Then he suddenly banked steeply to the left for he had just spotted a single plane tearing through the night sky over Thanet.
It might only be some amateur pilot practising night flying but, on the other hand, it just might be a single unit now detached from the smuggler squadron. Setting the controls, he pulled out his night glasses and focused them upon the solitary night flyer, then grunted with disappointment. It was not a big plane such as he had hoped to see, but a passenger machine, probably a four seater.
They were well inland now and heading west north-westward. The solitary plane was a thousand feet below them and, as Gregory came down, he picked up a long irregular broken chain of lights upon his right which, although the town was dark and the holidaymakers long since sleeping, indicated the deserted front at Margate.
A few moments more and he could see the sea again; the north Kentish coast where it runs towards the Thames estuary. Westgate, Birchington and Herne Bay lay somewhere ahead of him.
The other plane was dropping now towards a great belt of trees a little inland from Birchington. Their massed foliage stood out darkly in the faint starlight against the flat arable land which surrounded them on every side. The ring of trees was at least two miles in circumference and several broad open spaces in its centre suggested that the place was a private park.
From his greater altitude Gregory watched the solitary plane through his night glasses as it descended. Another moment and, circling into the wind, it floated down towards one of the bare patches in the very heart of the great belt of trees.
Instantly Gregory swung away to the south again; knowing that immediately the other plane landed its engine would be switched off and the roar of his own machine would attract attention.
Diving now to gain speed he headed away from the big tree girt enclosure, then flattened out and returned ten minutes later at a height sufficient only to ensure escaping that aerial death trap, the grid system, with its thousands of pylons now forming a network over England.
As he sighted the tall treetops again, standing out stark and black against the naked Thanet landscape, he decided to chance any pylons and risk a landing. A broad field lay below him. He could not guess if it was corn already harvested or stubble, but switching on his landing light he turned his plane towards the prevailing wind, and came down gently.
His luck was in. The plane bounded lightly for fifty yards and he was able to bring it to a standstill without turning over.
'Stay here,' he shot at Rudd. 'If the village constable happens to be on the prowl after poachers say we had to make a forced landing and that I've gone for petrol. Better get out the corkscrews and picket the plane in case the wind gets up. The machine we followed may have nothing to do with the outfit I'm after, but anyhow I'm going into this place to find out a bit more about it. I may be away some time.'
'I get you, sir,' Rudd muttered, and Gregory tumbled out on to the ground.
The field was ridged with coarse stubble; but he was soon out of it and across the low ditch into a winding lane which followed the curve of a thick, six-foot hedge, overhung by the leafy branches of massed trees on its far side.
The place was evidently a private park and a splendid site for secret landings, Gregory thought, remembering the several fine open meadows, separated by patches of woodland, but all enclosed within this outer belt of trees which surrounded it entirely.
He ran lightly along the lane, hoping to find a break in the hedge or a place where he could scramble over easily, but it was in good repair and he covered two hundred yards before he found a suitable spot.
A grassy bank below the hedge sloped up a little for a foot or more and from it protruded the stump of an old tree. By mounting on the stump he was able to fling himself bodily on the top of the hedge and slip down on the far side.
It was pitch dark there and he did not dare to use his torch; not knowing how deep the ring of trees might prove at this point and fearing that a light might be spotted by the people who had landed in the plane.