‘I must think it over,’ he said.  And then he suddenly began to talk about something else.

8

Arthur’s manner, troubled rather than indignant, had been against him.  He had dismissed the idea of a libel action, and not proposed to confront his libellers in a personal interview.  Every circumstance seemed against him.  I knew that, as I walked back to the laboratory after lunch.

And yet—­and yet.

Well, perhaps, as Jukie would say, it wasn’t my business.  My business at the moment was to carry on investigations into the action of carbohydrates.  Arthur Gideon had nothing to do with this, nor I with his private slayings, if any.

I wrote to Jukie that evening and told him I had warned Arthur, who apparently knew already what was being said, but didn’t seem to be contemplating taking any steps about it.

So that was that.

Or so I thought at the time.  But it wasn’t.  Because, when I had posted my letter to Jukie, and sat alone in my room, smoking and thinking, at last with leisure to open my mind to all the impressions and implications of the day (I haven’t time for this in the laboratory), I began to fumble for and find a new clue to Arthur’s recent oddness.  For twenty-four hours I had believed that he had perhaps killed Oliver Hobart.  Now, suddenly I didn’t.  But I was clear that there was something about Oliver Hobart’s death which concerned him, touched him nearly, and after a moment it occurred to me what it might be.

‘He suspects that Jane did it,’ I said, slowly and aloud.  ’He’s trying to shield her.’

With that, everything that had seemed odd about the business became suddenly clear—­Arthur’s troubled strangeness, Jane’s dread of meeting him, her determined avoidance of any reference to that night, her sudden fit of crying, Arthur’s shrinking from the idea of giving the talk against him publicity by a libel action, his question, ‘Does Jane know?’ his remark, to himself, that there was only one way of stopping it.  That one way, of course, would be to make Jane tell her parents the truth, so that they would be silenced for ever.  As it was, the talk might go on, and at last official investigations might be started, which would lead somehow to the exposure of the whole affair.  The exposure would probably take the form of a public admission by Jane; I didn’t think she would stand by and see Arthur accused without speaking out.

So I formed my theory.  It was the merest speculation, of course.  But it was obvious that there was something in the manner of Oliver Hobart’s death which badly troubled and disturbed both Arthur and Jane.  That being so, and taking into account their estrangement from one another, it was difficult not to be forced to the conclusion that one of them knew, or anyhow guessed, the other to have caused the accident.  And, knowing them both as I did, I believed that if Arthur had done it he would have owned to it.  Wouldn’t one own to it, if one had knocked a man downstairs in a quarrel and killed him?  To keep it dark would seem somehow cheap and timid, not in Arthur’s line.