Following a little wait, it swung slowly out, perhaps eighteen inches, the man advancing with it and again halting to peer up and down the street.  Then quickly, as if alarmed, he withdrew, shut the gate, and disappeared, closing the service-door behind him.

Listening intently, Lanyard heard no click of latch, such as should have been audible in that dead hour of hush.  Evidently the fellow had neglected to make fast the gate.  Possibly he had been similarly remiss about fastening the door.  But what was he up to?  Why this furtive appearance, why the retreat so abruptly executed?

By way of answer came the soft drone of a high-powered motor; then the car itself rolled into view, a stately limousine coming from the direction of the avenue de Friedland.  Before the corner house it stopped.  A lackey alighted with an umbrella and ran to hold the door; but Liane Delorme would not wait for him.  The car had not stopped when she threw the door open; on the instant when its wheels ceased to turn she jumped down and ran toward the house, heedless of the rain.

At the same time one side of the great front doors swung inward, and a footman ran out to open the gates.  The lackey with the umbrella, though he moved briskly, failed to catch up with Liane before she sped up the steps.  So he closed the umbrella and trotted back to his place beside the chauffeur.  The footman shut gates and door as the limousine moved away:  it had not been sixty seconds at rest.  In fifteen more street and house were both as they had been, save that a light now shone through the plate glass of the latter’s great doors.  And that was soon extinguished.

Conceiving that the man who had appeared at the service entrance was the same who had admitted Liane, Lanyard told himself he understood:  impatient for his bed, the fellow had gone to the service gate to spy out for signs of madame’s return.  Now if only it were true that he had failed to close it securely——!

It proved so.  The gate gave readily to Lanyard’s pull.  The knob of the small door turned silently.  He stepped across the threshold, and shut himself into an unlighted hall, thoughtfully apeing the negligence of the servant and leaving the door barely on the latch by way of provision against a forced retreat.

So far, good.  He felt for his pocket torch, then sharply fell back into the nearest corner and made himself as inconspicuous as might be.  Footsteps were sounding on the other side of an unseen wall.  He waited, breathless, stirless.

A latch rattled, and at about three yards’ distance a narrow door opened, marked by a widening glow of light.  A liveried footman—­beyond a doubt he who admitted the mistress of the house—­entered, carrying an electric candle, yawned with a superstitious hand before his mouth and, looking to neither right nor left, turned away from Lanyard and trudged wearily back to the household offices.  At the far end of the long hallway a door closed behind him—­and Lanyard moved swiftly.