Sydney moved forward to put his threat into execution.  As he did so, a strange alteration took place in Mr Holt’s demeanour.

CHAPTER XXX

THE SINGULAR BEHAVIOUR OF MR HOLT

I was standing in the middle of the room, Sydney was between the door and me; Mr Holt was in the hall, just outside the doorway, in which he, so to speak, was framed.  As Sydney advanced towards him he was seized with a kind of convulsion,—­he had to lean against the side of the door to save himself from falling.  Sydney paused, and watched.  The spasm went as suddenly as it came,—­Mr Holt became as motionless as he had just now been the other way.  He stood in an attitude of febrile expectancy,—­his chin raised, his head thrown back, his eyes glancing upwards,—­with the dreadful fixed glare which had come into them ever since we had entered the house.  He looked to me as if his every faculty was strained in the act of listening,—­not a muscle in his body seemed to move; he was as rigid as a figure carved in stone.  Presently the rigidity gave place to what, to an onlooker, seemed causeless agitation.

‘I hear!’ he exclaimed, in the most curious voice I had ever heard.  ‘I come!’

It was as though he was speaking to someone who was far away.  Turning, he walked down the passage to the front door.

‘Hollo!’ cried Sydney.  ‘Where are you off to?’

We both of us hastened to see.  He was fumbling with the latch; before we could reach him, the door was open, and he was through it.  Sydney, rushing after him, caught him on the step and held him by the arm.

’What’s the meaning of this little caper?—­Where do you think you’re going now?’

Mr Holt did not condescend to turn and look at him.  He said, in the same dreamy, faraway, unnatural tone of voice,—­and he kept his unwavering gaze fixed on what was apparently some distant object which was visible only to himself.

‘I am going to him.  He calls me.’

‘Who calls you?’

‘The Lord of the Beetle.’

Whether Sydney released his arm or not I cannot say.  As he spoke, he seemed to me to slip away from Sydney’s grasp.  Passing through the gateway, turning to the right, he commenced to retrace his steps in the direction we had come.  Sydney stared after him in unequivocal amazement.  Then he looked at me.

‘Well!—­this is a pretty fix!—­now what’s to be done?’

‘What’s the matter with him?’ I inquired.  ‘Is he mad?’

’There’s method in his madness if he is.  He’s in the same condition in which he was that night I saw him come out of the Apostle’s window.’  Sydney has a horrible habit of calling Paul ‘the Apostle’; I have spoken to him about it over and over again, —­but my words have not made much impression.  ’He ought to be followed,—­he may be sailing off to that mysterious friend of his this instant.—­But, on the other hand, he