`I had an object,' the doctor pronounced, slowly.

`Had you?' muttered Captain Mitchell. `Well, that's lucky, or else I would have thought that you went on fooling him for the fun of the thing. And perhaps that was your object. Well, I must say I personally wouldn't condescend to that sort of thing. It is not to my taste. No, no. Blackening a friend's character is not my idea of fun, if it were to fool the greatest blackguard on earth.'

Had it not been for Captain Mitchell's depression, caused by the fatal news, his disgust of Dr Monygham would have taken a more outspoken shape; but he thought to himself that now it really did not matter what that man, whom he had never liked, would say and do.

`I wonder,' he grumbled, `why they have shut us up together, or why Sotillo should have shut you up at all, since it seems to me you have been fairly chummy up there?'

`Yes, I wonder?' said the doctor, grimly.

Captain Mitchell's heart was so heavy that he would have preferred for the time being a complete solitude to the best of company. But any company would have been preferable to the doctor's, at whom he had always looked askance as a sort of beachcomber of superior intelligence partly reclaimed from his abased state. That feeling led him to ask:

`What has that ruffian done with the other two?'

`The chief engineer he would have let go in any case,' said the doctor. `He wouldn't like to have a quarrel with the railway upon his hands. Not just yet, at any rate. I don't think, Captain Mitchell, that you understand exactly what Sotillo's position is--'

`I don't see why I should bother my head about it,' snarled Captain Mitchell.

`No,' assented the doctor, with the same grim composure. `I don't see why you should. It wouldn't help a single human being in the world if you thought ever so hard upon any subject whatever.'

`No,' said Captain Mitchell, simply, and with evident depression. `A man locked up in a confounded dark hole is not much use to anybody.'

`As to old Viola,' the doctor continued, as though he had not heard, `Sotillo released him for the same reason he is presently going to release you.'

`Eh? What?' exclaimed Captain Mitchell, staring like an owl in the darkness. `What is there in common between me and old Viola? More likely because the old chap has no watch and chain for the pickpocket to steal. And I tell you what, Dr Monygham,' he went on with rising choler, `he will find it more difficult than he thinks to get rid of me. He will burn his fingers over that job yet, I can tell you. To begin with, I won't go without my watch, and as to the rest -- we shall see. I dare say it is no great matter for you to be locked up. But Joe Mitchell is a different kind of man, sir. I don't mean to submit tamely to insult and robbery. I am a public character, sir.'

And then Captain Mitchell became aware that the bars of the opening had become visible, a black grating upon a square of grey. The coming of the day silenced Captain Mitchell as if by the reflection that now in all the future days he would be deprived of the invaluable services of his Capataz. He leaned against the wall with his arms folded on his breast, and the doctor walked up and down the whole length of the place with his peculiar hobbling gait, as if slinking about on damaged feet. At the end farthest from the grating he would be lost altogether in the darkness. Only the slight limping shuffle could be heard. There was an air of moody detachment in that painful prowl kept up without a pause. When the door of the prison was suddenly flung open and his name shouted out he showed no surprise. He swerved sharply in his walk, and passed out at once, as though much depended upon his speed; but Captain