'Thanks.'

Biggles, followed by Ginger, went on as directed. Biggles stopped outside number twenty-two, unlocked it and went in. He switched on the light and closed the door behind him. He laid a finger on his lips warningly.

'Careful,' he breathed. 'There may be dictaphones.' Then he smiled.

'We're doing very nicely, aren't we?' he said softly.

'It's too easy,' replied Ginger suspiciously. 'All traps are easy to get into. It's the getting out that's the job.'

'I'm not thinking of getting out,' returned Biggles, taking his small-kit from his bag and putting it on the dressing-table.

'Ross and this bloke Stresser are in the next room,' said Ginger doubtfully. 'Isn't that a bit too close to be comfortable?'

'On the contrary, I think it's all to the good,' said Biggles, examining the walls. 'I want to talk some more to Stresser. I have an idea he might let something drop. At all events he seems to have a grievance against his employers. Such men are usually ready to blab to anyone who will listen to their troubles. I wouldn't trust him a yard.'

'What about something to eat?' suggested Ginger.

'Yes, we shall have to have a bite,' admitted Biggles. 'There doesn't appear to be a dining-room in this shabby joint, so presently I'll ask Stresser if he knows of a place where we can get a meal at a reasonable price. No doubt he does. I'm hoping he'll tell us where he eats himself.

We could join him there. After a little food and a drink he may thaw out a bit. It should make Ross feel more comfortable, too, if he sees us around.'

In the event, this little plan did not mature; for when, after a wash, Biggles went to the next room, a tap on the door produced no response.

From the proprietor he learned that Stresser and his companion had gone out. He did not say where they had gone. He may not have known.

But he named a small restaurant not far away where a reasonable meal could be obtained. Biggles went to the place hoping to find Stresser there, but in this he was disappointed. He and Ginger had a mediocre meal. They lingered over their coffee, but Stresser did not put in an appearance.

In fact, to Biggles' chagrin, they did not see either Stresser or Ross again that night. They heard them come home, but it was after midnight, and Biggles could not think of a reasonable excuse for starting a conversation at such a late hour.

The night pa.s.sed without incident.

The following morning Biggles was on the move early, for he had no intention of letting his man slip through his fingers if it could be prevented.

'What are you going to do?' asked Ginger, as they dressed.

'What we do will depend entirely on what Stresser does with Ross,'

returned Biggles. 'For the moment I am concerned only with keeping them in sight. It's no use thinking beyond that.'

'If we go on following Ross, Stresser, unless he is a nitwit, will get suspicious.'

'I'm afraid you're right. But we daren't lose sight of him.' 'Suppose they go to Russia?'

'That's something I'd rather not think about. But, whatever happens, we can't abandon Ross.'

'Of course not.'

'Then stop worrying. The luck has been good so far. It may go on. Always ride your luck while it lasts. The time to fret is when it goes against you. There's a chance that Ross may have learned something. If he has, he'll find a way to pa.s.s the gen on to us. For the moment we'll pack our kit, pay the bill, and then stick around to see what happens, ready to move fast if necessary.'

They went down to find the front door open. The proprietor, half dressed, was sweeping the floor. When Biggles asked for his bill he showed no emotion. This matter settled, Biggles explained that he was expecting a caller, so he would, if there was no objection, leave the bags in the vestibule until such time as he and his friend were ready to leave.

To this arrangement the proprietor agreed, and then went on with his work. After a while a woman called him, whereupon he stood his broom against the wall and disappeared through a door into the back premises, leaving Biggles and Ginger alone. As an excuse for being there they sat on a shabby sofa and made a pretence of reading papers taken from the table.

Soon afterwards a car pulled up outside. Glancing over the top of his paper, Ginger saw a man come in a" another client, presumably, from the confident way he strode to the stairs and went up. He wore a heavy overcoat with a fur collar, and carried fur gloves, which struck Ginger as odd, for while it was not exactly hot the weather could not be called cold. It did not occur to him that the man might have any connection with his own business.

'I'd say they have some queer customers here,' he murmured to Biggles.

Biggles' eyes were still on the stairs. They switched to Ginger. 'Yes,'

he said slowly.

Ginger sensed something. 'What's on your mind?'

'That fellow's fur coat and gloves.'

'What about them?'

'In Paris Stresser said something to me about a fur coat. I wonder?'

What Biggles wondered was not revealed, for at that moment the sound of voices approaching the top of the stairs caused him to break off short.

Three men appeared.

They were Stresser, Ross and the man with the fur collar. But it was to Ross that Ginger's eyes were drawn. He, too, now wore a heavy overcoat. It had not been b.u.t.toned, so that, swinging open, it showed that he no longer wore his dark suit.

He appeared to be wearing a drab grey uniform, in the manner of a battledress. On his head he wore a round fur cap, with earflaps tied on top. Stresser wore neither hat nor coat. The implication was plain.

He was not going out. The others were.

What followed occupied only a minute of time. As the three of them moved towards the door, only one showed that he was aware of Biggles and Ginger sitting there. Ross. As his eyes pa.s.sed over them they seemed to flicker, as if he were trying to convey a signal.

At the same time a tiny white object dropped from his fingers to the floor. There was no time for more. Ross shook the hand that Stresser held out to him and then he and his new escort were outside. The car door slammed. The engine started. Then, to Ginger's utter dismay, Stresser turned to Biggles, making it impossible for either of them to follow a natural impulse a" which was to rush out and seek a means of following the car a"

without making it obvious that they were shadowing Ross. Nor was it possible, without the action being observed, to pick up the object which Ross had dropped.

'That's another one gone,' said Stresser, his lips parting in a twisted smile to expose decayed teeth.

'Where does he go from here?' asked Biggles, with a nonchalance he did not feel.

'The usual place.'

'Not a nice day for flying,' ventured Biggles, firing a shot in the dark.

Stresser shrugged. 'The weather is better along the route, they say.'

Ginger could have struck the man for his non-committal replies.

Apparently he was not such a fool as he looked. At any rate, he was giving nothing away.

'And now, I suppose, you are free to go home?' suggested Biggles, looking at Stresser.

'Yes. I now go back to Berlin for further orders.' Stresser started to walk on, but a thought seemed to strike him. 'Which way are you going?'

he asked.

'We are to wait here for the time being.'

'So. Ah, well. I may see you on the Berlin plane.'

'We'll look out for you if we go that way,' promised Biggles.

Stresser walked on. But he was not out of sight when the proprietor came back and, picking up his broom, continued his task of sweeping the floor.

Biggles moved towards the object Ross had dropped. But he was just too late to retrieve it. It had fallen on that part of the floor which had already been swept, but the hotel keeper spotted it, and with a deft flip of his broom it was in a dustpan.

Ginger, whose nerves were on edge, could have cried out. 'Hark!'

exclaimed Biggles, raising a warning finger.

The proprietor stopped what he was doing to look at him. 'What is it?'

'I thought I heard someone call out in the kitchen.'

The proprietor put his dustpan on the reception desk, rested the broom against it, and then turned towards the rear of the building. The instant he was out of sight, Biggles'

fingers were in the dustpan, turning over the dirt, match sticks and cigarette ends it contained. An exclamation of satisfaction told Ginger that he had found what he was looking for. Without looking at it, Biggles put it in his pocket.

'What is it?' asked Ginger.

'No time to look now,' snapped Biggles. 'Jump to it. We've got to get back to the airport.

Our only hope is to find Ross there. Every second counts.' So saying he slammed on his hat, s.n.a.t.c.hed up his bag, and, striding through the open door to the pavement, looked up and down for a taxi.

None was in sight.

'Are you sure Ross is flying?' queried Ginger.

'No, I'm not sure,' replied Biggles crisply, 'but Stresser's remark about the weather suggested that he was. Come on.'

Together they hastened down the street towards a broad thoroughfare that crossed it at the end. Here there was a good deal of traffic, and after a brief delay they were able to pick up a cab. Biggles ordered the driver to take them to the airport.

'What's the drill when we get there?' inquired Ginger in a low voice.

'If we can't get on the same plane as Ross we might still be in time to see which way he goes,' replied Biggles.

'What was the thing he dropped?'

'A sc.r.a.p of paper rolled into a ball.' Biggles took the object from his pocket, unrolled it, and smoothed it on his knee.

Ginger saw that only one word had been written. The word was 'Kratsen.'

His eyes went to Biggles' face. 'Does that mean anything to you?' he asked.

'Not a thing.'

'Looks as if it might be the name of a place.'

'If it is, I haven't the remotest idea where it is on the map. It could be the name of anything, or a person. One thing is certain. Whatever the word stands for it must have meant something vital to Ross. He must have been pushed for time when he wrote it, or he would have said more. He had time for just one word, and that's it. Pity we couldn't have spoken to him; but it's no use thinking about that now. We can't expect the luck all our own way. We'll deal with the mystery later. Here we are.'

The car was now pulling up at the airport, outside the main entrance.

Biggles jumped out, paid the fare, and walked on into the big booking-hall, looking around anxiously. It was, it seemed, the busy hour, and there were a lot of people about, both coming and going.

From the concrete ap.r.o.n beyond came the clatter of aero motors. A big Berlin transport was discharging its pa.s.sengers. Biggles paid no attention to them, his efforts being concentrated on finding Ross and his new escort.

It was Ginger who at last spotted them. 'There they go,' he said shortly, inclining his head towards a barrier through which the men they sought were at that moment pa.s.sing.

Biggles strode to the gate, but not having a ticket was not allowed to go through; so all he and Ginger could do was stare at the retreating figures as they walked towards a twin-engined pa.s.senger plane that was clearly on the point of taking off.

'Call him!' urged Ginger desperately.

'Daren't risk it,' muttered Biggles. 'If we call attention to ourselves here, we've had it.

The place will be stiff with snoopers.'

'What machine is that they're making for?'

'An L 1-2. Russian job. Crib of the Douglas.'

'Find out where it's bound for.'

Biggles turned to the man in charge of the barrier and put the question.

But at that moment the man slammed the gate, drowning his words, and walked out on to the concrete. The engines of the aircraft roared.

Biggles stared at the machine as it began to move. There was nothing he could do. 'We'

ve lost him,' he muttered bitterly. Ginger had never seen his face so grim.

Helpless, they watched the machine take off. Then Biggles said: 'Let's go to the inquiry office and see what we can learn there.' He turned away abruptly, and in doing so collided with one of the several pa.s.sengers of the Berlin plane who were now leaving the Customs office.

'Sorry,' apologised Biggles. The word seemed to die on his lips as he found himself looking into the eyes of the last man he expected to see there. It was Erich von Stalhein.

For an instant, the expression on the German's face made it clear that his astonishment was as great as Biggles. But he had for long been trained in the hard school of experience, and he recovered his equanimity quickly. 'Good morning, Bigglesworth,' he said suavely. 'I hardly expected to see you here.'

Biggles smiled faintly. 'I certainly didn't expect to see you, either,'

he admitted.