dared give me no particulars about himself. I was simply
to select a third party whom I could trust, and to follow out his
instructions, which were those that I sent to you in my letter."

Jimmie Dale began to pace nervously up and down the room.

"Nothing else?" he queried, a little blankly.

"Nothing else," she said monotonously.

"But since last night, since you knew that things had gone wrong," he
persisted, "surely you traced that telephone number--the one you called
up?"

"Yes," she said, and shrugged her shoulders in a tired way. "Naturally
I did that--but, like everything else, it amounted to nothing. He
telephoned from Makoff's pawnshop on that alley off Thompson Street,
and--"

"WHERE!" Jimmie Dale, suddenly stock-still, almost shouted the word. "He
telephoned from--where! Say that again!"

She looked at him in amazement, half rising from her chair.

"Jimmie, what is it?" she cried. "You don't mean that--"

He was beside her now, his hands pressed upon her shoulders, his face
flushed.

"Box number four-two-eight!" He laughed out hysterically in his
excitement. "John Johansson--box number four-two-eight! And like a fool
I never thought of it! Don't you see? Don't you know now yourself? THE
UNDERGROUND POST OFFICE!"

She stood up, clinging to him; a wild relief, that was based on her
confidence in him, in her eyes and face, even while she shook her head.

"No," she said frantically. "No--I do not know. Tell me, Jimmie! Tell me
quickly! You mean at Makoff's?"

"No! Not Makoff's--at Spider Jack's, on Thompson Street!"--he was
clipping off his words, still holding her tightly by the shoulders,
still staring into her eyes. "You know Spider Jack! Jack's little
novelty store! Ah, you have not learned all of the underworld yet!
Spider Jack is the craftiest 'fence' in the Bad Lands--and Makoff is
his partner. Spider buys the crooks' stuff, and Makoff disposes of it
through the pawnshop--it's only a step through the connecting back yard
from one to the other, and--"

"Yes--but," she interrupted feverishly, "the package--you said--"

"Wait!" Jimmie Dale cried. "I'm coming to that! If Travers stood in with
Makoff, he stood in with Spider Jack. For years Spider has been a sort
of clearing house for the underworld--for years he has conducted, and
profitably, too, his underground post office. Crooks from all over
the country, let alone those in New York, communicate with each other
through Spider Jack. The