Biggles c.o.c.ked an eye at Ginger. 'How did you know?'

'Because when I saw him, von Stalhein was wearing one a" possibly the one that would make up a dozen in the box. I noticed it particularly because I've never seen von Stalhein wear anything but a plain black tie.'

'We shall have to think about that,' said Biggles. 'Tell me, Inspector; what did our friend do at Caterham?'

'Same as before. He spoke to some soldiers and had a long talk with Ross.'

'His movements were the same as the last time we watched him.' The detective got up. '

That's the lot. I've still got a man on the job. I'll let you know any developments.' He went out.

Biggles sat staring at the others. 'Ginger, you might take a walk round the West End shops in the morning and see if you can find any black ties with red spots. If you do, buy one or two.'

Ginger's eyebrows went up. 'What for?'

'Just an idea,' murmured Biggles.

'I've got an idea, too,' put in Algy. 'Before a man can get out of this country and into another he needs a pa.s.sport. All these recruits of von Stalhein must have had one. Ross would need one if he went. How does von Stalhein get British pa.s.sports?'

'There wouldn't be much difficulty about that,' returned Biggles, 'These fellows could all travel on the same pa.s.sport, if it comes to that. When it had served its purpose it could be sent back and used again. The photograph and the entries could be erased and fresh ones subst.i.tuted.

There are plenty of spare British pa.s.sports in Eastern Europe, anyway. In the Spanish Civil War, all the British contingent of the International Brigade had their pa.s.sports taken from them. They didn't get them back.

We know where they went.'

The telephone rang. Biggles picked up the receiver. 'Good. I'll be with you in half an hour,' he said, and hung up. 'That was the adjutant at Caterham,' he told the others. 'He's got Ross with him. Stick around till I get back.'

He was away for the best part of two hours.

'Now what?' inquired Ginger when he returned.

'We've made a little progress a" not much,' answered Biggles, dropping into his chair. '

Ross had a long talk with von Stalhein today a" we already knew that. I've just had a word with Ross. Under the pretence of being inclined to accept the offer, he's picked up a detail or two. When he is ready to go he is given a suit of civilian clothes, money, pa.s.sport and an air ticket from London to a European airport.

There he will be met by a man who will tell him what to do next.

Sat.u.r.day was suggested as the best time to go, because on that day Ross can get a week-end pa.s.s. That gives him plenty of time to get clear. Ross says he tried hard to get more information, but there was nothing doing.

Which means that we shan't get any further along that particular line of inquiry.'

'Did you fix up with Ross to accept?' asked Algy.

'Not yet. He said he was willing to go. I told him to do nothing more until he hears from me again.'

'What's the next move?'

'I've decided to tell Raymond about it. This thing is too big for us to carry on our own hook. The Air Commodore will probably have gone home, in which case I'll go to his house. There's no need for you to stay. I shall probably be late. You needn't wait up for me unless you want to. I'll get along.'

The Air Commodore was not in his office. Biggles went to his home, and caught him just as he was leaving for the club, where he usually dined.

Aware that Biggles would not trouble him at such a late hour unless he had urgent news to impart, he asked him to join him. Biggles accepted, and over the meal, in a quiet corner of the dining-room, revealed the plot he had uncovered.

The Air Commodore's expression hardened as he listened to the story, but he said nothing until Biggles had finished. Even then it was a little while before he spoke. 'This is a pretty state of affairs,' he said bitterly. 'There was a time when our enemies were content to steal our secrets. Now they entice away our troops. What do you suggest doing about it?'

'I feel inclined to let Ross go, and follow him,' said Biggles. 'I can't see any other course.

For their sakes, as well as our own, we can't just abandon these fellows who have already taken the bait. Anyhow, we must find out where they are.'

'If Ross goes, he'll take his life in his hands.'

'So shall we all. Ross knows the danger.'

'Don't, for goodness sake, do anything to start a war.'

Biggles frowned. 'Surely that's what the other side is doing now? They can't expect us to sit back and do nothing about it. I doubt if any country implicated would kick up a fuss if we were caught in their territory, because if the thing became public it would mean exposing their own hand as well as ours.'

'How can you follow Ross without being seen yourself? Von Stalhein will not lose sight of him, you may be sure, until he's actually on his way.'

'That will have to be arranged. I think it could be managed.' 'You mean, as he will go by air, you'd follow in one of your machines?'

'Yes.'

'What if it comes to night flying? You'd lose your man in the dark. Or, for that matter, suppose Ross, when he's abroad, is switched suddenly to surface travel a" a private car, for instance?'

'That'll be my worry,' said Biggles shortly. 'I can think of a score of unpleasant possibilities; but, as I said just now, what's the alternative?'

'We could pick up von Stalhein and so put an end to the business.'

'You might pick up von Stalhein, but how could you be sure that would end the business?

The chances are that he would simply be replaced by someone else. It's better to deal with a devil we know than one we don't know. Besides, to grab von Stalhein would tell the enemy we know what's going on. That would definitely mean saying goodbye to these silly fools who have already been hooked.'

Still the Air Commodore hesitated. He looked worried. 'I don't like it, Bigglesworth. It sounds too much like attempting the impossible. You might get behind the Iron Curtain by dropping in from an aircraft; but I can't see you getting out again. Without knowing the country you couldn't arrange for a machine to pick you up. You couldn't even get a message home to say where you were. Once in, you would probably disappear as completely as a stone dropped in the middle of the Atlantic. Every hand would be against you. Think of the language difficulties. You wouldn't be able to move about, get fooda"'

'Just a minute, sir,' broke in Biggles. 'I've taken all these things into account. I won't deny it's risky; but someone has to take risks. The biggest difficulty of all will be keeping Ross in sight. If I lose him, he's had it. He'd never get out on his own a" unless I could get in touch with him again.'

'How could you do that? Wander about Europe in the hope of meeting him?'

The Air Commodore was frankly sarcastic.

'No. There's only one way. We should have to decide on a rendezvous before the start. If I lost him, I should go there and wait. On the other hand, he could make for the same meeting place.'

'What meeting place?'

'That's where you'll have to help us.'

'What do you mean?'

'I imagine we have our own agents behind the Curtain. I also imagine that they have means of getting in touch with home, or they would serve no useful purpose.'

'And I also imagine that the Intelligence Service will think twice before they give us such an address,' said the Air Commodore grimly.

'It's asking a lot, I know. But I think the occasion warrants it. If they refuse a" well, we shall have to manage on our own. But such an address would make all the difference to our chances.'

The Air Commodore rolled breadcrumbs into little b.a.l.l.s. 'Another trouble is, there is so much territory behind the Iron Curtain. This International Unit might be anywhere between Poland and Bulgaria.'

'True enough. But I have a feeling that we shall find it in Czechoslovakia.'

'Why there?'

'All the evidence we have points to it. Ross had a letter from Prague a" I saw the postmark. Von Stalhein has a Czech pa.s.sport, which presumably he uses. When I go I shall, with your a.s.sistance, carry a Czech pa.s.sport for the same reason. We have people who could provide that I suppose?'

The Air Commodore gave ground reluctantly. 'Even if you found these fellows, how could you get them out of the country?' he argued.

'We should have to fly them out. There could be no other way.' 'That would be a nice job to undertake.'

'We've tackled worse.'

The Air Commodore drew a deep breath. 'All right,' he said wearily. 'Have it your own way. Even if you don't bring these men back, it will be something if you can find out what they're doing. Tell me exactly what you think you'll require and I'll do my best to procure it.'

The discussion was continued until the small hours. When Biggles finally reached home he found the others still up, waiting for him.

'Well, what's the verdict?' asked Algy.

Biggles sank into a chair and reached for a cigarette. 'I'm going to ask Ross to go.'

'The Chief has agreed to that?'

'Yes. He wasn't happy about it. Neither am I, for that matter. He could see the difficulties of trying to keep Ross in sight.'

'So can I,' murmured Ginger.

'If we can get a line on the general direction, or on the country to which von Stalhein's recruits are being sent, it will be something to go on with,' a.s.serted Biggles. 'Anyway, in the morning I shall tell Ross to accept. From what has been said, he will probably start his journey on Sat.u.r.day afternoon.'

'But how can you possibly keep an eye on him, old boy, without being spotted by that wily old fox, von Stalhein?' inquired Bertie, rubbing his eyegla.s.s.

'I've been turning that over in my mind all day,' Biggles told him.

'Gaskin will have to help us for the first part of the business. I shall ask him to shadow von Stalhein from the time Ross says he's willing to go. The first thing von Stalhein will have to do is to book a pa.s.sage. If he is watched, we should learn the time and place of Ross's departure. It seems certain he will go by air. I shall arrange for Ginger to be inside the machine, possibly in the radio cabin, until it is airborne. I'm a.s.suming that von Stalhein won't travel with Ross. I shall be sitting on the tarmac in the Proctor when Ross's machine takes off. I shall follow it a" or, rather, head for the same destination. You, Algy and Bertie, will stand by for radio signals from me, ready to act as I direct. That's only a rough outline of the general idea. We'll work out the details tomorrow. We mustn't forget to change our registration letters. Now let's see about getting some sleep.'

CHAPTER IV.

By Air a" to Where?

ABt a quarter to three on the following Sat.u.r.day afternoon iggles sat in the c.o.c.kpit of a police Proctor aircraft that had been put in a place convenient for the observation of pa.s.sengers who had booked for the three o'clock British European Airways service to Paris.

The big machine was already drawn up to receive its freight, human and otherwise. Inside, by arrangement with the Traffic Manager, was Ginger, in a position from which he could not be seen from outside.

These arrangements were not guesswork. They were based on definite information, the result of a good deal of trouble on the part of more than one department at Scotland Yard.

So far, everything had gone smoothly. Indeed, as far as Biggles knew, they had gone without a hitch, and he was actually in possession of more information than he expected to get. This was brought about largely by the close and efficient co-operation of Inspector Gaskin and his highly-trained staff.

Guardsman Ross, who had thrown himself wholeheartedly into the undertaking regardless of its perilous nature, had told von Stalhein that he had decided to accept his invitation to join the International Corps; whereupon von Stalhein, watched by Gaskin's men, had lost no time in making the necessary arrangements.

These need not be dwelt upon in detail, but they exposed two more members of the spy organisation, one a photographer and the other a small printer, in the East End of London. They were left alone for the time being. What was of greater importance to Biggles was the booking by von Stalhein of a single pa.s.sage to Paris, by British European Airways, on the three o'clock Sat.u.r.day plane. The seat had been taken in the name of Ross. From the fact that von Stalhein had not troubled to change the name of his recruit, Biggles could only suppose that he felt he was on safe ground.

Nothing of importance had transpired at the final interview between Ross and the German. Ross told his adjutant, who pa.s.sed the information on to Biggles, that they were to meet at the 'Stand Easy' caf at a quarter-past one; and in due course this appointment was kept. From that moment Ross and von Stalhein were under surveillance.

They had gone together to von Stalhein's suite at the Grosvenor Hotel.

When they emerged, and went into the dining-room for a meal, Ross was apparently ready for the journey, for he was now dressed in a dark suit and soft hat, and carried a suitcase. An interesting detail was, he wore a red-spotted black tie. Biggles, who was waiting at the airport with Ginger, had received this information direct from Inspector Gaskin.

'What do you make of this spotted tie business?' Ginger had asked Biggles.

'I can only think that it's for purposes of identification,' replied Biggles. 'We'll put ours on. They can do us no harm even if they do no good.'

Ginger, following Biggles' instructions to procure the ties, had found them in a shop in Piccadilly. This was only one of several minor preparations that had been put in hand as soon as it had been decided that Ross should accept von Stalhein's invitation.

Doc.u.ments, which included pa.s.sports, were prepared. Sums of money, in several foreign currencies, were procured. Into the linings of jackets had been inserted 'escape'

equipment designed to aid prisoners of war a" tiny steel files, miniature compa.s.ses, and maps which, folded, were no larger than a postage stamp.

In providing these Biggles was thinking not so much of himself as of Ross, and the men he hoped to release. As he remarked with a smile: 'It's often little things like this that count.'

At the last minute he had rung up Marcel Brissac, his opposite number of the International Police Commission in Paris, and asked him to meet him off the plane at Le Bourget, the Paris airport which it seemed was to be the first stop. He had no particular reason for doing this. It struck him that it might be useful to have official a.s.sistance at the airport should there be trouble of any sort. 'There's a chance that there may be a man waiting for the London plane who wears a black tie with red spots,' he told Marcel. 'If so, check up on him and see if he books a pa.s.sage for anywhere.' Marcel agreed to do this.

For luggage, Biggles and Ginger each carried only a small handbag containing nothing more questionable than small-kittoilet things, pyjamas, and a spare shirt and socks.

Air Commodore Raymond had done all that Biggles had required of him. This was not much, but it was of paramount importance. He had obtained a name and address in Prague, which those engaged in the case, including Ross, could use as a hide-out, and from where, in dire emergency, a message could be got home. This address had of course been committed to memory.

So the stage was set for what Biggles knew was likely to prove one of the most hazardous operations he had ever undertaken.

The motor-coach bringing the pa.s.sengers from London now arrived, and very soon the travellers were making their way towards the aircraft. Biggles saw von Stalhein talking earnestly to Ross, presumably giving him final instructions. For a moment a smile softened Biggles' expression as he saw Inspector Gaskin in the background, also watching.

Ross took his place in the machine. Von Stalhein retired.

Biggles waited for no more, for there was no likelihood of any change of plan on either side. He asked Control for permission to take off, and having received it, he taxied out.

In a minute or two he was in the air, heading for Paris. By arriving first he would be able to watch the pa.s.senger plane come in, and have time to look over the people waiting for it. With von Stalhein out of the way there would be no danger in this. He hoped also to have a chat with Marcel.

He found Marcel waiting, and having put the Proctor out of the way he lost no time in coming to the point. 'Any clients wearing spotted ties?'