passed them.  Now and then a taxicab sped through the avenues of darkness like a criminal pursued by the impalpable.  Now and then a red light flickered in a porch instead of a white one.  But there was no surcease from the sinister spell until suddenly they emerged into a long, wide, illumined thoroughfare of shut shops that stretched to infinity on either hand.  And a vermilion motor-bus meandered by, and this motor-bus was so sad, so inexpressibly wistful, in the solemn wilderness of the empty artery, that the two women fled from the strange scene and penetrated once more into the gigantic and fearful maze from which they had for an instant stood free.  Soon they were quite lost.  Till that day and night Audrey had had a notion that Miss Ingate, though bizarre, did indeed know every street in London.  The delusion was destroyed.

“Never mind,” said Miss Ingate.  “If we keep on we’re bound to come to a cabstand, and then we can take a taxi and go wherever we like—­Regent Street, Piccadilly, anywhere.  That’s the convenience of London.  As soon as you come to a cabstand you’re all right.”

And then, in the distance, Audrey saw a man apparently tampering with a gate that led to an area.

“Why,” she said excitedly, “that’s the house we’re staying in!”

“Of course it isn’t!” said Miss Ingate.  “This isn’t Paget Gardens, because there are houses on both sides of it and there’s a big wall on one side of Paget Gardens.  I’m sure we’re at least two miles off our beds.”

“Well, then, how is it Nick’s hairbrushes are on the window-sill there, where she put them when she went to bed?  I can see them quite plain.  This is the side street—­what’s-its-name?  There’s the wall over there at the end.  Don’t you remember—­it’s a corner house.  This is the side of it.”

“I believe you’re right,” admitted Miss Ingate.  “What can that man be doing there?”

They plainly saw him open the gate and disappear down the area steps.

“It’s a burglar,” said Audrey.  “This part must be a regular paradise for burglars.”

“More likely a detective,” Miss Ingate suggested.

Audrey was thrilled.

“I do hope it is!” she murmured.  “How heavenly!  Miss Foley said she was being watched, didn’t she?”

“What had we better do?” Miss Ingate faltered.

“Do, Winnie?” Audrey whispered, tugging at her arm.  “We must run in at the front door and tell Supper-at-nine-o’clock.”

They kept cautiously on the far side of the street until the end of it, when they crossed over, nipped into the dark porch of the house and rang the bell.

Susan Foley opened for them.  There was no light in the hall.

“Oh, is there?” said Susan Foley, very calmly, when she heard the news.  “I think I know who it is.  I’ve seen him hanging round my scullery door before.  How did he climb over those railings?”

“He didn’t.  He opened the gate.”