aroused.  Then he took it to the small window of the air shafts hanging it on a hook which was half concealed behind the ledge.  Down this he lowered himself, hand over hand.  The stone was quickly lifted—­it was hinged on the under surface. n the dark hole which was before him there was an iron ladder.  Down he went, into the utter blackness.  His outstretched hands apprised him that he was at the beginning of a walled tunnel, through which he groped in a half-upright position.  He reached an iron door, and remembering his direction calculated that this must be at the rear entrance of the old garage on West Fifty-fifth Street.  It opened, as he swung a heavy iron bar, fitted with a curious mechanism resembling the front of a safe.  Softly he entered, carrying his heavy boots in his hand.  All was still within, and he shot the glow ray of his little lamp about him.  As the reader may guess, it was the rear room of Warren’s private spider-web!  The table, facing the screen was surmounted by an ingenious telephone switchboard.

Shirley examined this closely.  The various plugs were labelled:  “Rector,” “Flatbush,” “Jersey City,” “Main,” “Morningside,” and other names which Shirley recognized as “central” stations of the telephone company.  Here was the partial solution of the mysterious calls.  He determined to test the service!

He took up the telephone receiver and sent the plug into the orifice under the label, “Co.” wondering what that might be.  Soon there was an answer.

“Yes, Chief.  What is it?”

“How’s everything?” was Shirley’s hoarse remark.  “I find connections bad in the Bronx?  What’s the matter?”

“I’ll send one of the outside men up there to see, Chief.  There’s a new exchange manager there, and he may be having the wires inspected.  But my tap is on the cable behind the building.  I don’t see how he could get wise.”

Shirley smiled at this inadvertent betrayal of the system:  wire tapping with science.  He was able to trap the confederate with his own mesh of copper now.

“I want to see you right away.  Some cash for you.  I’m sick with a cold in the throat so don’t keep me waiting.  Go up town and stand in the doorway at 192 West Forty-first Street.  Don’t let anybody see you while you wait there, so keep back out of sight.  How soon can you be there?”

“Oh, in half an hour if I hurry.  Any trouble?  You certainly have a bum voice, Chief.  But how will I know it’s you?”

“I’ll just say, ‘Telephone,’ and then you come right along with me, to a place I have in mind.  Don’t be late, now!  Good-bye.”

Shirley drew out the connection and tried the exchange labelled “Rector.”  Instantly a pleasant girl’s voice inquired the number desired.

“Bryant 4802-R.”

This was the Hotel California.

The operator on the switchboard of the hostelry replied.

“Give me Miss Marigold’s apartment, please.”