The agent shrugged his shoulders with a fatalistic gesture. 'Who knows?'

'I don't - that's why I asked you,' murmured Bertie.

'One hour - two hours - maybe three,' was the vague reply.

Really! By Jove! Well, don't be too long. And I say, be careful with that box of fireworks up topsides, won't you?'

She is safe,' declared the man. The fuse she is fixed for fifteen minutes. That give me time to get clear.'

'I wasn't thinking about you, old top,' continued Bertie cheerfully, as he helped his accomplice into his seat and then climbed into his own c.o.c.kpit.

Two minutes later he was in the air, climbing steeply, and after an uneventful flight over the Channel began a long furtive glide through the wavering searchlight beams that lined the French coast. These were only to be expected and he was not perturbed; which clearly was more than could be said for the pa.s.senger, for every time a fresh beam stabbed the sky he struck Bertie on the shoulder and pointed to it.

'I say, old chap, you really must sit still,' shouted Bertie at last. 'They won't hurt you.' He had an uncomfortable feeling that the man was nervous.

This was confirmed a few minutes later when, in spite of his efforts to slip across the coast un.o.bserved, some 'flak' came up, although it burst at a safe distance. The agent sprang up in his seat.

'Go back!' he shouted.

'Why?' asked Bertie amazed.

'We are seen. We are shot at.'

'Look here, my lad, if you don't sit down I'll conk you on the bean with my gun,' roared Bertie, beginning to get angry.

The man continued to protest, whereupon Bertie threw a loop. After that there was silence, and he glided on through the beams towards his objective. He was satisfied that the searchlights had not picked him up. Gliding at little more than staffing speed the machine made no noise, and he watched the lights dowse one by one behind him.

The actual landing was the most trying part of the operation, for there was always a risk of the field being trapped' - that is, prepared by the enemy for the reception of machines engaged in special missions, the trap taking the form of obstacles calculated to crash a machine as it glided in. For a moment or two as the Moth swept low across the marsh which he had selected for his landing-ground, Bertie held his breath. Then the wheels touched lightly and the aircraft ran on to a smooth landing. He climbed down.

'Here we are,' he said cheerfully. I suppose you saw the jolly old ca.n.a.l as we came down? It's only about a quarter of a mile away - over there.' He pointed to the north, and then leaned forward in order to see his companion's face, for he had heard a slight sound that puzzled him. It was as if the man's teeth were chattering.

'I say, old fellow, what's the matter? Are you cold?' he asked anxiously.

The man did not answer. He pa.s.sed down his parcel and then got down himself, peering into the darkness.

Bertie saw that he had not been mistaken. The man was trembling violently.

'It is dangerous, zis place,' he breathed.

Fiddlesticks!' answered Bertie. 'What did you think you were coming on - a picnic?

Off you go.'

The man hung back.

Bertie mustered all the tolerance in his nature. 'Now look here, my lad,' he said seriously, just you trot along and do your stuff. The sooner the job's done the sooner we go home.

My coffee will be getting cold.'

Still the man hesitated, and Bertie knew that he was in for trouble. Consequently, he was relieved when, in a moment or two, the man picked up his parcel and disappeared into the night. But the relief was shortlived. Inside a minute he was back.

'Here, I say, what's the matter?' asked Bertie quickly. 'You really can't go on like this.

Hop along, there's a good chap. I'm getting chilly.'

'You will be here - yes?' inquired the man anxiously.

Bertie kept his temper. 'Of course I'll be here. Get a move on. We don't want to stick around here all night. I'm getting my feet wet.'

The agent made an inaudible remark and set off again, while Bertie made preparations for a quick take-off when he returned. So engrossed was he in his task that he started violently when, a few seconds later, a voice spoke from the other side of the machine.

But it was only the agent again.

Bertie ducked under the fuselage and joined him. 'Now look here, you really can't go on like this,' he protested.

'It ees impossible!' cried the other excitedly.

Bertie stared. What's that?'

Zere are soldiers.'

What have they got to do with it?'

'But soldiers!'

'You've just said that,' Bertie pointed out. What did you expect to find - a jolly old mothers' meeting? Come on now, be a good boy; toddle along and let off your fireworks or I shall start to get angry with you - yes, by jingo!'

'But zee soldiers will see me.'

'Not they. I'll bet they're playing pontoon or something. I know! If they come towards you make a noise like a horse.'

The man shook his head. 'No, I am not so brave,' he said huskily.

Of course you are,' persisted Bertie. 'You're as brave as a lion - anyone can see that.'

'No. Tonight it ees impossible. We come back another time - perhaps tomorrow.'

Bertie took a pace nearer. His voice was ominously calm. 'Tomorrow won't do, my white-livered little rabbit.'

He was wondering what he ought to do, for there was no time to return to the aerodrome and report what had happened. Already the barges would be approaching the lock. There seemed to be only one answer. He tapped his useless confederate on the chest with a calculating forefinger.

'Now you listen to me, my n.o.ble gladiator. You stay here and look after the machine.

Can you manage that?'

The agent looked horrified. It was obvious that his one idea was to get back across the Channel as quickly as possible.

Bertie perceived this. When he spoke again his voice was gentle, but behind it lay a crisp, vibrant ring that had not previously been there.

'If you're not here with this aircraft when I come back, the next time I see you I'll cut off your legs, sharpen the stumps, and drive you into the ground with a mallet- by Jove, I will! - you mark my words.' With this parting admonition he picked up the parcel and made off in the direction of the lock.

A walk of a few minutes was sufficient to convince him that the man was at least right in one respect. Seven or eight soldiers were standing on or about the lock and, judging by a faint glow of light that issued from the guard-house window, it seemed likely that there were more inside. Unfortunately, in every direction the country was open, bare, and desolate; a mouse could hardly have approached the lock without being observed.

This is awkward - deuced awkward,' he mused, as he put down his load and stopped to consider the problem.

A minute's reflection was sufficient for him to realize that conditions were unlikely to be changed and that any attempt to get near the lock was doomed to failure from the start.

Still, the idea of returning to the aerodrome with the mission incomplete was unthinkable, and he refused to consider it.

With no fixed plan in his mind he struck off at a tangent towards the ca.n.a.l, reaching it some distance above the lock. It was, he found, a turgid-looking stream, supported on either side by raised banks. Where were the barges? He looked up and down the shining ribbon of water, and although in the moonlight he could see for a considerable distance, there was no sign of them. He glanced at his luminous wrist-watch. It was three minutes to nine.

'These Intelligence chappies don't live up to their name,' he ruminated. It looks as if they'

ve made a mistake in their beastly calculations, and the boats have either pa.s.sed hours ago or are still ambling along near Arras. I'd better see if I can find them.' With his dangerous parcel under his arm he set off along the towing-path.

After covering about two hundred yards he came to a bend, and as he rounded it an exclamation broke from his lips, for his eyes fell on something he had not bargained for, although at first it did not occur to him that it might be of service. It was a footbridge, an elevated, flimsy wooden structure that spanned the ca.n.a.l from side to side linking two footpaths. As he stood regarding it he heard a sound that set his pulses racing. It was the chug-chug-chug of engines.

'By Jove, here come the beastly barges,' he breathed, staring up the ca.n.a.l to where a long line of dark shadows had appeared on the placid water. For a moment or two he hesitated, thinking swiftly, and then drew a deep breath. If it comes off it ought to be fun,' he told himself. If it doesn't, I'm afraid that silly a.s.s I brought here will have to walk home.' He waited no longer but, crouching low, ran quickly to the footbridge and wormed his way to the middle of it.

He had not long to wait, although in the circ.u.mstances the minutes seemed like hours.

Slowly but surely the heavy boats, low in the water, crept nearer. He removed the cover from the parcel by his side. He found the firing plunger and forced it home. 'I hope that chappie didn't make any mistake about that fuse,' he murmured.

Lying flat, he looked along the line of boats, the first one now less than fifty yards away and the others following at short intervals. They looked unreal. He could see the steersman of the leading boat clearly, a burly fellow, smoking a long pipe as he leaned against the heavy rudder. Were there any other men on board? He did not know, but he hoped not. With his revolver in his right hand and the bomb in his left, he waited until the barge drew level. The bows pa.s.sed under the bridge, creating a sensation that he himself was moving. He tensed his muscles; then, as the steersman drew level, he dropped; and as he dropped, he struck.

But an object moving in the dark is a deceptive target; moreover, he was to some extent enc.u.mbered by his burden. And instead of the b.u.t.t of the revolver hitting the man on the head as he intended, it caught him on the shoulder.

His startled cry was cut short by Bertie, who landed on top of him, and together they rolled down the short companionway into the cabin.

Bertie, being the more agile, was up first. He had dropped the bomb, but he still retained his grip on the revolver, although he dare not make full use of it because of the alarm the report would inevitably cause. So, grasping the muzzle and swinging the weapon like a club, he sprang at the bargee. But his adversary was no fool and, seeing how Bertie was armed, he promptly sent the candle, which provided the only light, spinning across the room.

Now Bertie was not so foolish as to enter willingly into a wrestling bout with a man twice his weight - certainly not in the dark; so he darted up the steps and vaulted over the low superstructure at the top. He was round in a flash, crouching low, waiting for the man who he felt certain would follow him. And he was not mistaken. He heard him muttering and cursing in German as he came blundering up the stairs; but it seemed that he had a good idea of what to expect, for as Bertie struck at him again he ducked with surprising agility, and Bertie all but lost his balance. But he did not lose his head, and as the man jumped clear he leapt at him like a cat.

The German instinctively stepped backwards, evidently forgetting where he was, which was close to the outside extremity of the deck. He made a desperate effort to keep his balance, but Bertie, seizing his opportunity, dashed in and knocked him over backwards.

There was a terrific splash as the man went overboard.

Bertie waited long enough to see him start swimming towards the bank, and then turned his attention to the bomb. As near as he could judge, the fuse had been burning for five minutes, which gave him another ten minutes' grace; so he picked it up and ran along the side of the barge looking for the best place to put it. Heavy black tarpaulins had been lashed over the cargo, and for this reason he could not see it; nor had he time to investigate, for the boatman was now running along the bank yelling at the top of his voice. Hunting about quickly, Bertie found a part.i.tion between two tarpaulins just about amidships, and this, he decided, would have to suit his purpose. He thrust the bomb into the gap, and then looked about anxiously for a way of escape.

The situation was even worse than he expected. The second barge, apparently suspecting that something was wrong, had closed up until it was only a few yards behind. From the opposite direction, the direction of the lock, a party of soldiers was running along the towing-path, on the same side of the ca.n.a.l as he had left the aircraft. There seemed to be only one course left open to him, and he lost no time in taking it. Seizing the rudder, he threw his weight against it and brought the barge over until it was running along within a few feet of the opposite bank - that is to say the bank farthest from the soldiers, who were now less than fifty yards away. He wondered vaguely why they did not shoot, for he knew that they must be able to see him; then he remembered the dangerous cargo the barge carried, and understood their reluctance to use firearms.

At this moment a second man, who must have been asleep below, came scrambling up to the deck. He let out a yell when he saw what was happening.

Bertie waited no longer. He took a flying leap at the bank, landed on all fours, and threw himself over the embankment just as a bullet whistled past his ear. But the embankment was as good as the parapet of a trench, and he took advantage of it, running like a plover towards the bridge as fast as his legs could carry him. When he was about half-way he risked a peep at the opposite bank, and saw at a glance that his hopes of getting back to the machine, via the bridge, were very slim, for two or three of the soldiers had kept pace with him and were likely to reach the bridge before him. He perceived that the nearer to the bridge he went, the nearer he would be to the Germans when they crossed over, for such was obviously their intention, so he turned off at a tangent, making for a wood that stood on some rising ground not far away.

Two or three shots were fired as he ran, but none came near him and, reaching his immediate objective, he looked back in the direction of the lock to see what was going on. At first he could not quite make out what had happened, but it seemed as if the leading barge had run into the bank a few yards short of the lock. The next one, possibly because it had too much way on it to stop, had pa.s.sed it; the others had closed up and stopped, to await their turn to pa.s.s through the lock.

Curiously enough, Bertie had either forgotten the bomb or else he was unaware that the time limit had expired; at any rate no thought of it was in his mind when the explosion occurred. At first there was a single, sharp, clearly defined detonation, but it was followed instantly by an explosion, and a blast of air so violent that even at that distance it threw him to the ground. For a full minute the roar persisted, like a continuous roll of thunder while the heavens were lighted up by an orange glare that revealed the landscape as clearly as if it were broad daylight. Then the light faded, and the terrible roar was succeeded by an ominous silence. Perhaps it would be more correct to say a comparative silence, for in a moment Or two strange sounds were borne on the air, the most clearly defined being the noise of rushing water.

'By jingo, that was a bit hot,' muttered Bertie, groping about for his eyegla.s.s, which had been blown from his face by the concussion. He soon realized the futility of trying to find it in such conditions, so getting up, he stared towards the lock trying to make out what had happened. The landscape seemed to have changed. Of the lock and the barges there was no sign. The ca.n.a.l no longer gleamed in the moonlight. It appeared now as a sinister black shadow that widened swiftly as it neared the place where the lock had been, and thereafter lost itself in a turbulent lake that seemed to reach to the horizon.

'By Jove, I'm afraid that's done it,' he muttered uneasily, as a horrid thought entered his head. A second and more penetrating look, and his worst fears were realized. Where the lock had been, the bank of the ca.n.a.l had completely disappeared. So had the lock. The water, millions of gallons of it, had poured through the breach, with the result that the ca.n.a.l was practically empty. But it was not this that upset him. It was the direction in which most of the water had overflowed. From where he stood he could not see his machine, but if it was still where he had left it - which seemed unlikely - then it was in the middle of a lake. Of the German troops who had run up the towing-path there was no sign, and It could only a.s.sume that they had gone back to the scene of the explosion.

He started off towards the ca.n.a.l, crossed over the bridge, and entered the water that covered the low-lying marsh on the other side. This, he was relieved to find, was only ankle-deep in most places, with occasional deeper patches. In these conditions it was not easy to locate the exact spot where he had left the aircraft, but when he reached what he felt certain was the place, that which he feared might have happened was confirmed. It had gone. On all sides stretched the water, and had it not been for an occasional tree and hedge, he might have been gazing at an ocean.

A faint hail attracted his attention. He recognized the voice and hurried towards the spot.

As he approached he could just make out the shape of the machine. When he got to it he found the agent standing in his seat, muttering incoherently; but Bertie paid no attention to him; he was concerned only with the aircraft which, as far as he could make out, had been lifted bodily by the first rush of the flood and swept away until a hedge had arrested its progress. The fabric was torn in several places, but a quick examination revealed no sign of structural damage.

Hi, fellow, come on out of that and help me to straighten her up,' he told his useless accomplice curtly.

The amateur agent continued to protest that all was lost, whereupon Bertie, his patience exhausted at last, swung himself up, caught the man by the scruff of the neck and dragged him bodily out of the c.o.c.kpit.

'One more bleat from you, my little sheep, and I'll give you a kick in the pants that will make you think you've sat on a rocket. Come along now and give me a hand.'

Between them they got the machine clear of the hedge, facing the open water. The engine was started and they scrambled into their seats.

The take-off was a nightmare. A seaplane would not have raised as much spray. But the light machine unstuck at last, and with a jubilant Yoicks 1' Bertie headed for home, which he reached without further mishap.

The entire squadron was waiting for him when he landed. How did you get on?' asked Biggles eagerly, as Bertie jumped down.

Oh, not bad, sir, not half bad,' answered Bertie.

It all went off according to plan, eh?'

'No jolly fear it didn't,' declared Bertie soberly.

What went wrong?'

Something pretty serious,' announced Bertie. 'I lost my beastly eyegla.s.s in the dark. I call that pretty steep, don't you - what ?'