If Mr Nark’s theory of how cyanide got on the dart was ever understood by himself he had no gift for imparting it to others. He became incoherent, and defensively mysterious. He dropped hints and, when pressed to explain them, took fright and dived into obscurities. He uttered generalizations of bewildering stupidity, assumed an air of huf-finess, floundered into deep water, and remained there blowing like a grampus. Alleyn was about to leave him in this plight when, perhaps as a last desperate bid for official approval, Mr Nark made a singular statement.

‘The Garden of Eden,’ he said, ‘as any eddicated chap knows, is bunk. You can’t tell me there’s any harm in apples. I grow ‘em. Us started off as a drop of jelly. We’ve come on gradual ever since, working our way up through slime and scales and tails to where we are. We had to have a female to do the job. Us knows that. Biological necessity. But she’s been a poisonous snare and a curse to us as even the ignorant author of Genesis had spotted and noted down in his foolish fashion, under cover of a lot of claptrap. She’s wuss than a serpent on her own, and she’s mostly always at the back of our troubles. Searchy la fem as the French detectives say and you ought to bear in mind. This ghastly affair started a year ago and there’s three alive now that knows it. There was four.’

Alleyn realized with a sinking heart that he would have to pay attention to Mr Nark. He saw in Mr Nark a desire for fame struggling with an excessive natural timidity. Mr Nark hungered for the admiring attention of the experts. He also dreaded the law, to which he seemed to accord the veneration and alarm of a neophyte before the altar of some tricky and fickle diety. Alleyn decided that he must attempt to speak to him in his own language.

He said, ‘That’s very interesting, Mr Nark. Strange, isn’t it, Fox? Mr Nark has evidently—’ he fumbled for the magic word—‘evidently made the same deductions as we have from the evidence in hand.’

Fox gave his superior a bewildered and disgusted glance. Alleyn said rather loudly, ‘See what I mean, Fox?’

Fox saw. ‘Very striking, sir,’ he said. ‘We’ll have to get you into the force, Mr Nark.’

Mr Nark buttoned his coat.

‘What’ll you take, gentlemen?’ he asked.

But it was heavy going. To get any sense out of him Alleyn had to flatter, hint, and cajole. A direct suggestion threw him into a fever of incoherence, at a hint of doubt he became huffy and mysterious. As she seemed to be the only woman in the case, Alleyn attempted to crystalize on Decima.

‘Miss Moore,’ he said at last, ‘is naturally very much upset by Mr Watchman’s death.’