I had followed the wrong men.
There was nothing to do but go back to the Gare du Nord, and question more porters and cabmen.

Nobody could give me any information worth having, it seemed; yet the little man must have left the station in a vehicle of some sort, as he had a great deal of small luggage.

Since I could learn nothing of him or his movements, however, and dared not, because of Maxine and the British Foreign Secretary, apply to the police for help, I determined to lose no more time before consulting a private detective, a man whose actions I could control, and to whom I need tell only as much of the truth as I chose, without fear of having the rest dragged out of me.
At my own hotel I enquired of the manager where I could find a good private detective, got an address, and motored to it, the speed bracing my nerves.

Fortunately, (as I thought then) Monsieur Anatole Girard was at home and able to receive me.

I was shown into the plain but very neat little sitting-room of a flat on the fifth floor of a big new apartment house, and was impressed at first glance by the clever face of the dark, thin Frenchman who politely bade me welcome.