'Look,' said Sooty, taking them to the window. They saw that the little room had a view of the tower belonging to the house. It was the only room in the house that did, for it was built at a queer angle.
The boys looked — and Julian gave an exclamation. Someone was signalling from the tower! A light there flashed every now and again. In and out — pause — flash, flash, in and out — pause. The light went regularly on and off in a certain rhythm.
'Now — who's doing that?' whispered Sooty.
'Your father?' wondered Julian.
'Don't think so,' said Sooty. 'I think I heard him snoring away in his room. We could go and find out though — see if he really is in his bedroom.'
'Well — for goodness sake don't let's get caught,' said Julian, not at all liking the idea of prying about in his host's house.
They made their way to where Mr Lenoir had his room. It was quite plain he was there, for a regular low snoring came from behind the closed door.
'It may be Block up in the tower,' said Dick. 'He looks full of secrets. I wouldn't trust him an inch. I bet it's it Block.'
'Well — shall we go to his room and see if it's empty?' whispered Sooty. 'Come on. If it's Block signalling, he's doing it without Father knowing.'
'Oh, your father might have told him to,' said Julian, who felt that he wouldn't trust Mr Lenoir much further than he would trust Block.
They went up the back-stairs to the wing where the staff slept. Sarah slept in a room there with Harriet the kitchen-maid. Block slept alone.
Sooty pushed open Block's door very softly and slowly. When he had enough room to put in his head, he did so. The room was full of moonlight. By the window was Block's bed. And Block was there! Sooty could see the humpy shape of his body, and the black round patch that was his head.
He listened, but he could not catch Block's breathing. He must sleep very quietly.
He withdrew his head, and pushed the other two boys quietly down the back-stairs.
'Was he there?' whispered Julian.
'Yes. So it can't be him, signalling up in our tower,' said Sooty. 'Well — who can it be then? I don't like it. It couldn't possibly be Mother or Sarah or the little kitchen-maid. Is there a stranger in our house, someone we don't know, living here in secret?'
'Can't be!' said Julian, a little shiver running down his back. 'Look here — what about us going up to the tower and trying to peep through the door or something? We'd soon find out who it was then. Perhaps we ought to tell your father.'
'No. Not yet. I want to find out a whole lot more before I say anything to anyone,' said Sooty, sounding obstinate. 'Let's creep up to the tower. We shall have to be jolly careful though. You get to it by a spiral staircase, rather narrow. There's nowhere much to hide if anyone suddenly came down out of the tower.'
'What's in the tower?' whispered Dick, as they made their way through the dark and silent house, thin streaks of moonlight coming in here and there between the cracks of the closed curtains.
'Nothing much. Just a table and a chair or two, and a bookcase of books,' said Sooty. 'We use it on hot summer days when the breeze gets in strongly through the windows there, and we can see a long way all round us.'
They came to a little landing. From this a winding, narrow stairway of stone went up to the rounded tower. The boys looked up. Moonlight fell on the stairway from a slit-like window in the wall.
'We'd better not all go up,' said Sooty. 'We should find it so difficult to hurry down, three of us, if the person in the tower suddenly came out. I'll go. You stay down here and wait. I'll see if I can spy anything through the crack in the door or the key-hole.'
He crept softly up the stairway, soon lost to view as he rounded the first spiral. Julian and Dick waited in the shadows at the bottom. There was a thick curtain over one of the windows there, and they got behind it, wrapping its folds round them for warmth.
Sooty crept up to the top. The tower-room had a stout oak door, studded and barred. It was shut! It was no use trying to look through the crack, because there wasn't one. He bent down to peer through the key-hole.
But that was stuffed up with something, so he could not see through that either. He pressed his ear to it and listened.
He heard a series of little clicks. Click — click — click — click — click. Nothing else at all.
'That's the click of the light they're using,' thought Sooty. 'Still signalling like mad! What for? Who to? And who is in our tower-room, using it as a signalling-station? How I wish I knew!'
Suddenly, the clicking stopped. There was the sound of someone walking across the stone floor of the tower. And almost at once the door opened!
Sooty had no time to hurry down the stairs. All he could do was to squeeze into a niche, and hope that the person would not see him or touch him as he went by. The moon went behind a cloud at that moment, and Sooty was thankful to know he was hidden in black shadow. Someone came down the stairs and actually brushed against Sooty's arm.
Sooty jumped almost out of his skin, expecting to be hauled out of his niche. But the person did not seem to notice, and went on down the spiral stairway, walking softly.
Sooty did not dare to go down after him, for he was afraid the man would come out, and cast his shadow down for the signaller to see.
So he stayed squeezed in his niche, hoping that Julian and Dick were well-hidden, and would not think it was he, Sooty, who was walking down the stairs!
Julian and Dick heard the soft footsteps coming, and thought at first it was Sooty. Then, not hearing his whisper, they stiffened behind the curtains, guessing that it was the signaller himself who was walking by!
'We'd better follow him!' whispered Julian to Dick. 'Come on. Quiet, now!'
But Julian got muddled up with the great curtains, and could not seem to find his way out. Dick, however, slipped out easily enough, and padded after the disappearing person. The moon was now out again, and Dick could catch glimpses of the signaller as he went past the moonlight streaks. Keeping well in the shadows himself, he darted quietly after him. Where was he going?
He followed him across the landing to a passage. Then across another landing and up the back-stairs! But those led to the staff bedrooms. Surely the man was not going there?
Dick, to his enormous surprise, saw the person disappear silently into Block's bedroom. He crept to the door, which had been left a little ajar. There was no light in the room except that of the moon. There was no sound of talking. Nothing at all except a creak which might have come from the bed.
Dick peeped in, full of the most intense curiosity. Would he see the man waking up Block? Would he see him climbing out of the window?
He stared round the room. There was no one there at all, except Block lying in bed. The moonlight lit up the corners, and Dick could quite plainly see that the room was empty. Only Block lay there, and, as Dick watched, he heard him give a sigh and roll over in bed.
'Well! That's the queerest thing I ever saw,' thought Dick, puzzled. 'A man goes into a room and completely disappears, without a single sound! Where can he have gone?'
He went back to find the others. Sooty by this time had crept down the spiral staircase and had found Julian, who had explained that Dick had gone to follow the queer signaller.
They went to find Dick, and suddenly bumped into him, creeping along quietly in the darkness. They all jumped violently, and Julian almost cried out, but stifled his voice just in time.