Having reclosed the door, he turned and leaned in through the open window.

“Evidently you are not concerned, Mr. Cavanagh,” he said.  “Be warned.  Do not interfere with those that are!”

The night swallowed him up.

My fears had been justified; the man was one of the Hashishin—­a spy of Hassan of Aleppo!  What did it mean?

I craned from the window, searching the platform right and left.  But there was no sign of him.

When the train left Northampton I found myself alone, and I should only weary you were I to attempt to recount the troubled conjectures that bore me company to Birmingham.

The train reached New Street at nine, with the result that having gulped a badly needed brandy and soda in the buffet, I grabbed my bag, raced across—­and just missed the connection!  More than an hour later I found myself standing at ten minutes to eleven upon the H—­ platform, watching the red taillight of the “local” disappear into the night.  Then I realized to the full that with four miles of lonely England before me there hung above my head a mysterious threat—­a vague menace.  The solitary official, who but waited my departure to lock up the station, was the last representative of civilization I could hope to encounter until the gates of “Uplands” should be opened to me!

What was the matter with which I was warned not to interfere?  Might I not, by my mere presence in that place, unwittingly be interfering now?

With the station-master’s directions humming like a refrain in my ears, I passed through the sleeping village and out on to the road.  The moon was exceptionally bright and unobscured, although a dense bank of cloud crept slowly from the west, and before me the path stretched as an unbroken thread of silvery white twining a sinuous way up the bracken-covered slope, to where, sharply defined against the moonlight sky, a coppice in grotesque silhouette marked the summit.

The month had been dry and tropically hot, and my footsteps rang crisply upon the hard ground.  There is nothing more deceptive than a straight road up a hill; and half an hour’s steady tramping but saw me approaching the trees.

I had so far resolutely endeavoured to keep my mind away from the idea of surveillance.  Now, as I paused to light my pipe—­a never-failing friend in loneliness—­I perceived something move in the shadows of a neighbouring bush.

This object was not unlike a bladder, and the very incongruity of its appearance served to revive all my apprehensions.  Taking up my grip, as though I had noticed nothing of an alarming nature, I pursued my way up the slope, leaving a trail of tobacco smoke in my wake; and having my revolver secreted up my right coat-sleeve.

Successfully resisting a temptation to glance behind, I entered the cover of the coppice, and, now invisible to any one who might be dogging me, stood and looked back upon the moon-bright road.