“You’re quite right,” he said.  “I had made up my mind you should hear some of the truth tonight in any case; that was the chief reason why I asked you to come and pick me up.  When I saw you had brought Mr. Lyndon with you, I determined to tell you everything.  It’s the simplest and best way, after all.”

He stopped for a moment, and we all three sat there in silence, while the Betty slowly throbbed her way forward, splashing off the black water from either bow.  Then Latimer began to speak again quite quietly.

“I am in the Secret Service,” he said; “but you can forget the rest of what I told you the other night, Morrison.  I am after bigger game than a couple of German spies—­though they come into it right enough.  I am on the track of three friends of Mr. Lyndon’s, who just now are as badly wanted in Whitehall as they probably are in hell.”

I leaned back with a certain curious thrill of satisfaction.

“I thought so,” I said softly.

He glanced at me with his keen blue eyes, and the light of the lamp shining on his face showed up its square dogged lines of strength and purpose.  It was a fine face—­the face of a man without weakness and without fear.

“It’s nearly twelve months ago now,” he continued, “that we first began to realize at headquarters that there was something queer going on.  There’s always a certain amount of spying in every country—­the sort of quiet, semi-official kind that doesn’t do any one a ha’porth of practical harm.  Now and then, of course, somebody gets dropped on, and there’s a fuss in the papers, but nobody really bothers much about it.  This was different, however.  Two or three times things happened that did matter very much indeed.  They were the sort of things that showed us pretty plainly we were up against something entirely new—­some kind of organized affair that had nothing on earth to do with the usual casual spying.

“Well, I made up my mind to get to the bottom of it.  Casement, who is nominally the head of our department, gave me an absolutely free hand, and I set to work in my own way quite independently of the police.  It was six months before I got hold of a clue.  Then some designs—­some valuable battleship designs—­disappeared from Devonport Dockyard.  It was a queer case, but there were one or two things about it which made me pretty sure it was the work of the same gang, and that for the time, at all events, they were somewhere in the neighbourhood.

“I needn’t bother you now with all the details of how I actually ran them to earth.  It wasn’t an easy job.  They weren’t the sort of people who left any spare bits of evidence lying around, and by the time I found out where they were living it was just too late.”  He turned to me.  “Otherwise, Mr. Lyndon, I think we might possibly have had the pleasure of meeting earlier.”

A sudden forgotten recollection of my first interview with McMurtrie flashed vividly into my mind.