noisily in the wind.

The door was opened, presently, by a middle-aged lady of pleasant face
and courteous manner. She held a night-lamp high above her
night-capped head while she inspected the boys standing on the little
porch. Nestor broke into a merry laugh.

"Are you thinking of burglars, Aunty Jane?" he asked. Then he added,
"Burglars don't knock at doors, Aunty. They knock people on the head."

"Well, of all things, Ned Nestor!" exclaimed the lady, in a tone which
well matched her engaging face. "What are you doing here at this time
of night?"

"I want to leave a friend here for the day," was the reply. "Come,
Aunty, don't stand there with the lamp so high. You look like the
Statue of Liberty. Let us in and get us something to eat. I'm hungry."

"I suspected it" smiled the lady. "You always come to Aunty Jane when
you are hungry, or when you've got some one you are hiding. Well, come
in. I'm getting used to your manners, Ned."

The boys needed no second invitation to step inside out of the cold
wind. After Fremont had been presented to Aunty Jane, they were shown
to the sitting-room--an apartment warmed by a grate fire and looking as
neat as wax--where they waited for the promised breakfast.

"She is a treasure, Aunty Jane White," explained Nestor, as the boys
watched the cold March dawn creep up the sky. "She really is my aunt,
you know, mother's sister. She knows all about my love for secret
service work, and lets me bring my friends here when they want to keep
out of sight."

"You said something about leaving me here to-day," Fremont observed.
"Why are you thinking of doing that? Why not keep together, and both
get out of the city?"

"I can't tell you now," Nestor replied, a serious look on his face.
"I've got something to do to-day that is so important, so vital, that I
dare not mention it even to you. It does not concern your case, except
that it, too, points to Mexico, but is an outgrowth from it."

"Strange you can't confide in me," said Fremont, almost petulantly.

Nestor noted the impatience in his friend's tone, but made no reply to
it. He had taken a packet of letters from his pocket, and was running
them thoughtfully through his hands, stopping now and then to read the
postmark on an envelope.

"Do you remember," he asked, in a moment, "of seeing a tall shadow in
front of the door to the Cameron suite just before we left there?"

"I did not see any shadow there," was t