you think I am, anyhow?" he asked. "I must look like a
'come-on.'"

"I'm giving it to you straight," she said simply. "After you have made
out a good fat check, then you go to a store, buy something, tell them
to forward the check to the bank for certification, and that you'll send
for the goods and the change the next day. The bank always certifies the
check, and you get the money."

"Not always," said Peabody with a grin.

"No, not always," acquiesced Mrs. Parker. "But Jim and I have been
averaging over a hundred dollars a day for months."

"Good graft, all right," assented the detective. "But how does the one
who lays down the check identify himself? For instance, suppose I go
into Tiffany's and pick out a diamond, and say I'm Mr. John Smith, of
100 West One Hundredth Street, and the floorwalker says, 'Sorry, Mr.
Smith, but we don't know you,' what then?"

"Just flash a few letters on him," said the girl. "Letters and
envelopes."

"Where do you get 'em?" asked Peabody.

"Just write them, silly, and send them to yourself through the mail."

"That's all right," retorted the "second story man." "But how can I mail
myself a letter to 100 West One Hundredth Street _when I don't live
there_?"

Mrs. Parker smiled in a superior manner.

"I'm glad I can put you wise to a new game, I invented it myself. You
want letters of identification? In different names and addresses on
different days? Very good. Buy a bundle of stamped envelopes and write
your own name and address on them _in pencil_. When they arrive rub off
the pencil address. Then if you want to be John Smith of 100 West One
Hundredth Street, or anybody else, just address the cancelled envelope
_in ink_."

"Mabel," said Peabody with admiration, "you've got the 'gray matter' all
right. You can have _me_, if you can deliver the rest of the goods."

[Illustration: FIG.3.--A letter-head frill of Mabel Parker's.]

"There's still another little frill," she continued, pleased at his
compliment, "if you want to do the thing in style. Maybe you will find a
letter or bill head in the mail at the same time that you get your
sample check. If you do, you can have it copied and write your request
for the check book and your order for the goods on paper printed
exactly like it. That gives a sort of final touch, you know. I remember
we did that with a dentist named Budd, at 137 West Twenty-second
Street." (Fig. 3.)

"You've got all the rest whipped to a standstill,"