‘Great Scott!’ I cried, ’what a close shave!  I’m in the mood at this moment to shoot him at sight.  You say you saw him in Paris and knew his lair.  Surely you had a good enough case to have him collared.’

She shook her head.  ’Mr Blenkiron—­he’s in Paris too—­wouldn’t hear of it.  He hasn’t just figured the thing out yet, he says.  We’ve identified one of your names, but we’re still in doubt about Chelius.’

’Ah, Chelius!  Yes, I see.  We must get the whole business complete before we strike.  Has old Blenkiron had any luck?’

’Your guess about the “Deep-breathing” advertisement was very clever, Dick.  It was true, and it may give us Chelius.  I must leave Mr Blenkiron to tell you how.  But the trouble is this.  We know something of the doings of someone who may be Chelius, but we can’t link them with Ivery.  We know that Ivery is Bommaerts, and our hope is to link Bommaerts with Chelius.  That’s why I came here.  I was trying to burgle this escritoire in an amateur way.  It’s a bad piece of fake Empire and deserves smashing.’

I could see that Mary was eager to get my mind back to business, and with some difficulty I clambered down from the exultant heights.  The intoxication of the thing was on me—­the winter night, the circle of light in that dreary room, the sudden coming together of two souls from the ends of the earth, the realization of my wildest hopes, the gilding and glorifying of all the future.  But she had always twice as much wisdom as me, and we were in the midst of a campaign which had no use for day-dreaming.  I turned my attention to the desk.

It was a flat table with drawers, and at the back a half-circle of more drawers with a central cupboard.  I tilted it up and most of the drawers slid out, empty of anything but dust.  I forced two open with my knife and they held empty cigar boxes.  Only the cupboard remained, and that appeared to be locked.  I wedged a key from my pocket into its keyhole, but the thing would not budge.

‘It’s no good,’ I said.  ’He wouldn’t leave anything he valued in a place like this.  That sort of fellow doesn’t take risks.  If he wanted to hide something there are a hundred holes in this Chateau which would puzzle the best detective.’

‘Can’t you open it?’ she asked.  ’I’ve a fancy about that table.  He was sitting here this afternoon and he may be coming back.’

I solved the problem by turning up the escritoire and putting my knee through the cupboard door.  Out of it tumbled a little dark-green attache case.

‘This is getting solemn,’ said Mary.  ‘Is it locked?’

It was, but I took my knife and cut the lock out and spilled the contents on the table.  There were some papers, a newspaper or two, and a small bag tied with black cord.  The last I opened, while Mary looked over my shoulder.  It contained a fine yellowish powder.

‘Stand back,’ I said harshly.  ’For God’s sake, stand back and don’t breathe.’