, Sam, and having
failed to meet you at the Perrys' I decided to try and catch you here
before you left."

"But where on earth did you get that disguise?" demanded the doctor.

"I borrowed the clothes from Martha; fortunately, with padding, they
fit me quite well. She also lent me the key of your basement so that I
would not attract attention by going to the front door. The wig," Nancy
laughed, "I used that in some tableaux at one of the Sanitary Fairs
last year. It came in very handy, for the Secret Service men thought I
was old Martha and let me pass unquestioned."

"No wonder; your make-up is perfect," declared Boyd heartily.

"Have you secured the paper for me, Sam?" asked Nancy.

"Yes, Missy." Sam took a small slip of paper from an inside pocket and
handed it to her. Nancy studied the closely written lines intently.

"Important?" inquired the doctor, breaking the long silence.

"Very." She carefully refolded the slip. "This contains the key to
Stanton's private cipher code."

A low whistle of surprise escaped Boyd. "How did you get it?"

"Arthur Shriver, who, as you know, was a clerk in his office, copied
it, but before he could get it to me he was arrested on suspicion,"
explained Nancy. "I heard he was confined in one of the front rooms in
the Old Capitol Prison, and so arranged to have the sentry's attention
diverted while I questioned Arthur by prearranged signals."

"Did the plan work?"

"It did. Arthur told me where he had hidden the paper, and I sent Sam
to-night to get it for me."

"Well, well!" The doctor sat back and contemplated Nancy admiringly.
"There's another message written on the back of that paper."

Nancy turned it over and her eyes widened in surprise as she read aloud
the hastily scrawled words: "Mrs. Bennett is a Union spy. I have just
overheard an interview between her and Stanton."

"That woman!" ejaculated the doctor. "That cat!"

"Felines scratch," Nancy shrugged her shoulders disdainfully. "Stanton
is fighting the devil with fire."

"Be careful, Nancy; don't undervalue your opponents," cautioned the
doctor.

"I flatter myself I am a match for Mrs. Bennett," retorted Nancy, "and
forewarned is forearmed."

"Strange," muttered Doctor Boyd. "Very strange. Do you recollect
the----"

"I shall turn this paper over to you, Doctor," broke in Nancy
impetuously, "to take through the lines, along with a despatch which I
also secured to-night."

Boyd shook his head. "Impossib