Jones are on Earth.'
'Why do we have to pretend that we are on Earth,' said Crosby. 'We have been down on Earth all our lives.'
'Well, you know what I mean. Darbi and I are out in space and we are sending you messages,' said Jennings.
'All right,' said Jones. 'But I don't understand why we have to stay...'
'Don't argue, Crosby. We are on Mars, and you are down on Earth, and when you hear a tap on your dormitory window - you'll know that I've lowered the telephone.'
'All right,' said Crosby. 'We'll do what we can, but it will not be our fault if something goes wrong.'
'But nothing can be wrong,' said Jennings.
The members of Dormitory 6 took off their clothes very quickly that evening.
'Hurry up into bed, you boys,' Crosby said to his friends: 'Mr Wilkins is on duty. So let's not make him wait.'
'Why not?' they wanted to know.
'Because there will be a message from Mars after Mr Wilkins puts the light out,' explained Crosby.
'So don't ask him questions when he comes in to put the light out,' advised Jones. 'Say 'good night' and that's all.'
Mr Wilkins was surprised when he came into Dormitory 6 and found all the boys in their beds. He was also surprised when he saw that the boys were waiting for him to put out the light. He had noticed the same thing in Dormitory 4 which he had visited some minutes earlier. At the same time Mr Wilkins was very pleased. 'The boys now understood at last that they must behave themselves when the teacher on duty is L. P. Wilkins,' he thought.
He turned off the light.
'Good night, sir. ... Good night,' said Crosby at once.
'What do you mean - good night? I haven't gone yet.'
'No, but you are going, aren't you, sir?'
'I'll go when I'm ready, and not before,' said Mr Wilkins. 'I want to be sure that everybody is going to sleep before I go.'
He went to the window and for some minutes stood and looked down at the school yard.
'The dormitory is dark now,, and there will be a tap on the window at any moment,' thought Jones.
'You don't have to stay here specially for us, sir,' he said.
'That's all right. I'm not in a hurry,' said Mr Wilkins. He turned from the window and began to walk about the dormitory.
'I think I heard the bell for teachers' supper,' said Crosby.
'Really! Your sense of hearing must be wonderful...'
'Oh, yes, sir; it is, sir.'
'...if you can hear sounds before they happen. Now you'll tell me that you can hear...' Mr Wilkins stopped - he heard a tap on the window behind him. 'What was that?' he exclaimed. Dormitory 6 wanted to show that they did not hear anything. 'What was what, sir?' they asked. 'Didn't you hear anything now? Not even you Crosby, with your wonderful sense of hearing?'
Again a tap on the window. 'There it is again - a tap,' said Mr Wilkins and hurried back to the window.
'Yes, I think it is a tap, sir. The hot tap on the wash-basin often makes a funny noise, sir,' said Jones.
'No, no, no. Not a water tap, you silly little boy. Somebody is tapping 'on the window.'
Mr Wilkins opened the window and put his head out into the cool evening.
At the last moment Jennings saw that it was not Crosby's head, but Mr Wilkins', and quickly pulled the string up. So when Mr Wilkins looked down, then right and left, and then above his head he certainly did not see anything.
'It's too dark to see anything,' he said and shut the window. 'I'm going into the yard to see that all is well.'
Chapter Twenty-Eight
Jennings and Darbishire give the alarm
Mr Wilkins went out of Dormitory 6 and hurried to the school yard. In the hall he met Mr Carter.
'I say, Carter, something strange is going on in the school yard,' said Mr Wilkins. 'Somebody is tapping on Dormitory 6 window.'
Mr Carter smiled.
'Nonsense, Wilkins. I can't believe it. Nobody could tap on Dormitory 6 window from the ground without a ladder.'
'All right, all right. I'm just telling you what happened. I'm not trying to explain it,' said Mr Wilkins. 'Maybe he used a ladder.'
'You think that suddenly during the night somebody had a wish to clean windows. Well, really, Wilkins!'
'Of course not. I think that somebody was in the school yard. Somebody who disappeared when I looked out of the window. It could be a burglar.'
'I don't think so,' said Mr Carter. 'Why did a burglar have to choose that strange time and place.'
But Mr Wilkins was sure that there was somebody in the school yard.
'I didn't say there was a burglar. I said there could be,' he answered coldly. 'And I must find out who it was.'
'All right. I'll come with you,' said Mr Carter with a smile.
The two teachers went out and closed the door behind them. It was cold and the moon was shining brightly.
For some minutes they walked about the school yard, but, of course, they did not find anybody.
'I think you frightened him away when you put your head out of the window,' said Mr Carter and smiled again.
'You don't think there was a burglar, do you?' Mr Wilkins got angry. 'I see you don't believe me.'
'I certainly think that you were mistaken. But I think you were right to come out and see. And as there is nobody in the yard, let's go back and have our supper.'
But when they came up to the door they found that neither of them had a key. Mr Wilkins rang the bell. But there was no answer. Now they had to wait in the cool November evening. Half a minute later Mr Wilkins rang the bell again. After that he knocked and rang the bell again and again, but nobody came to answer. It was not surprising, because everybody was at that time having supper in the dining hall at the far end of the building.
Suddenly Mr Wilkins said, 'Never mind, Carter. I've now remembered that I saw an open window. It's a window in Classroom 2 which is on the ground floor. So you stay here, and I'll climb in and open the door for you.'
With these words Mr Wilkins hurried down the steps, turned round the corner of the building and came up to the window of Classroom 2. It was really open, and a moment later he was on the window-ledge, his head in the dark room and his feet still hanging over the window-ledge.
If only he had known with what interest two boys watched him from the window of Dormitory 4!
Fifteen minutes earlier Jennings had been greatly surprised to see Mr Wilkins put his head out of the window of Dormitory 6. He was so surprised that he nearly dropped the telephone on Mr Wilkins' head. Jennings quickly shut the window.
'Old Wilkie is still there,' he whispered to Darbishire.
'Are you sure?' his friend asked him.
'Of course I'm sure. I nearly dropped the telephone on his head when he put it out of the window.'
'You don't think he saw you, do you?' 'Oh, no, he didn't see me. But let's wait some minutes and give him time to leave the room before we try again.'
