"Nothing at all since the autumn. He appeared just for a short time, and then vanished again."

"And no one ever knew who he was?"

"Not a soul."

Pamela gave a long sigh.

"He has the secret--whatever it is. Who knows whether I'll ever find it.

Ave," here Pamela lowered her voice, "I've got a secret too! I've been longing and yearning to tell it to you--a dozen times I've had it on the tip of my tongue, and then I've felt afraid and stopped. I kept waiting, hoping to find out more, but I can't find out by myself. I want help."

"What do you mean?"

"Come, and I'll show you. We have the place to ourselves to-day. Uncle is in town. I saw him going to the station this morning, so he's not likely to burst in and interrupt us."

Pamela rose and led the way down the garden to the stable where Avelyn had surprised her before. It was locked, but she took a key from a hiding-place under a stone, and undid the padlock. She motioned her friend to go up the ladder, and followed her. The room above was a bare loft. It was not quite empty, however, for in the corner stood a small table, with an object on it that looked like the receiver of a telephone.

"Come here!" said Pamela.

She took up the instrument and placed it on her friend's head. It had a band which fitted across the forehead, and a receiver for each ear. A cord connected it with the wall.

"Do you hear anything?" asked Pamela.

"Yes, a sort of humming."

Pamela smiled significantly, and put back the instrument on the table.

"What is it?" breathed Avelyn, rather awed.

"Wireless messages. Uncle spends hours here."

"Do you mean to say this is a wireless station?"

Pamela nodded.

"But they're not allowed."

"I know that perfectly well."

"If it were found out he could be arrested."

"He deserves to be. Sometimes I wish he were."

"Does your mother know?"

"No, I'm sure she doesn't. She never comes to the stable, and if she did she wouldn't climb the ladder. Sometimes Uncle is very keen about the messages. He makes me stay here, with the receiver on my head, listening for them, while he sits in the cottage talking to Mother, and drinking brandy which he brings in a flask. When I hear that humming noise I have to go and tell him, and he flies down to the stable."

"Can you understand the messages?"

"No. It's something like ordinary telegraphy, I suppose, and I don't know the code. I wish I did."

"I can't imagine how this wireless apparatus hasn't been discovered!"

"It's so well hidden. The poles go right up among the boughs of the tree."

"I don't think you ought to keep this secret any longer, Pam."

"No more do I, but I've never dared to tell it to a soul before. Uncle would kill me if he knew I'd brought you in here to-day. What must I do?"

Avelyn hesitated.

"I'd like to ask somebody. Could you come home with me this afternoon?

Can you leave the house?"

"I'd lock the door and put the key under a stone, where Mother would find it if she gets back first. Ave, I'm just about desperate! I'd do anything to end the life I'm living now. There's treachery of some sort going on, I believe, and I'm being wound up in it without my knowledge and against my will. My father gave his life for his country. Is his daughter to help to betray it? Never! Never in this world! I'd suffer torture first. Oh, I wish I were braver! Sometimes I'm a terrible coward, and I feel so horribly afraid of Uncle Fritz. You don't know how he frightens me. My nerves are all on edge."

"Come home with me, dear," said Avelyn soothingly. "If you'll let me ask Mother, I believe she'd know what we ought to do."

Pamela was very much upset, and seemed almost hysterical. Her hands trembled, and she wiped tell-tale drops from her eyes. She climbed down the ladder, padlocked the stable door again, went into the house for her hat and the history book, locked the front door, hid the key in the rockery, and p.r.o.nounced herself ready to start.

Avelyn was glad to have persuaded her so easily. Her own mind was in a whirl. To have found a wireless telegraphy installation in the old stable was indeed a discovery which would very seriously implicate Mr.

Hockheimer. The responsibility of the knowledge was too great to be borne only by two schoolgirls; it must be shared by some older and wiser person.

The friends walked silently along the road. At the corner by the oak wood they met David and Anthony. At sight of them the boys came running forward in much excitement.

"We've just seen Spring-heeled Jack again!" they cried.

This was indeed a piece of news. Spring-heeled Jack, who had vanished from the neighbourhood since the autumn! For the moment it even threw wireless telegraphy into the shade.

"Where? When?" exclaimed the girls eagerly.

"Just a minute ago. We were up the bank there after a b.u.t.terfly, and he came bounding past and jumped into the wood."

"Which way did he go?"

Anthony pointed a stumpy finger to indicate the direction. Pamela set her teeth.

"I'm going after him," she announced.

The Watsons stared at her amazed. Spring-heeled Jack had been the terror of the village, and Pamela was not altogether conspicuous for courage.

"I must find him! I must!" she continued. "It's the only chance of getting that lost paper!" And climbing over the palings she scrambled into the wood among the bracken.

The Watsons were not a family to desert a chum. David and Anthony were after her in half a second, and Avelyn followed as quickly as her feminine skirts allowed. Her heart was beating violently. Whether the object of their search was human or spectral he was equally a cause for alarm. They could hear sounds higher up the wood. Pamela was running fast and so were the boys.

There was a sudden, unearthly yell, and a dark, masked figure came bounding towards them in a series of wild leaps. Man, monkey, or bogy, it jumped with incredible speed. The boys set up a shout and dashed towards it, but it gave an enormous leap and sprang past them. It would have got clean away but for a tangled bramble bush that broke its course. The next moment it was sprawling among the bracken. The boys rushed upon it, and while David pinned it down Anthony tore off the black mask. To their utter amazement it revealed the well-known features of their friend, Captain Harper.

At the sight of their blank faces he burst out laughing.