Mr. Neal considered a little. The mystery was thickening. The one
way out of it, so far, was the way traced faintly through that
strange story of the unfinished letter which the doctor had
repeated to him in Mrs. Armadale's words. The nearer he
approached his unknown responsibility, the more ominous it seemed
of something serious to come. Should he risk another question
before he pledged himself irrevocably? As the doubt crossed his
mind, he felt Mrs. Armadale's silk dress touch him on the side
furthest from her husband. Her delicate dark hand was laid gently
on his arm; her full deep African eyes looked at him in
submissive entreaty. "My husband is very anxious," she whispered.
"Will you quiet his anxiety, sir, by taking your place at the
writing-table?"

It was from _her_ lips that the request came--from the lips of
the person who had the best right to hesitate, the wife who was
excluded from the secret! Most men in Mr. Neal's position would
have given up all their safeguards on the spot. The Scotchman
gave them all up but one.

"I will write what you wish me to write," he said, addressing Mr.
Armadale. "I will seal it in your presence; and I will post it to
your executor myself. But, in engaging to do this, I must beg you
to remember that I am acting entirely in the dark; and I must ask
you to excuse me, if I reserve my own entire freedom of action,
when your wishes in relation to the writing and the posting of
the letter have been fulfilled."

"Do you give me your promise?"