te understand why Duvall, or Brooks, as he supposed him to be, was
dining here at the Minister's.

It was quite late when the party rose from the table, and, a little
while later, Grace, anxious to get away from the place, and be alone
with Richard, announced that she must return home. "Mr. Brooks has
kindly offered to escort me," she said, quickly, fearful that Dr.
Hartmann might suggest that she return with him.

The latter smiled coldly, his eyes fixed on her with a gleam of
suspicion. "I think I shall be going myself," he said, as he took leave
of the remainder of the party.

As they reached the sidewalk, Duvall observed the taxicab he had ordered
to be in readiness, standing in front of the door. He helped Grace
inside, then turned in some hesitation to the chauffeur. He dared not
tell the fellow to drive to the railway station, since Hartmann, who
stood beside the cab chatting with Grace, would inevitably hear him. He
therefore instructed the man to go to Dr. Hartmann's with the intention
of countermanding the order a little later, as soon as they had got out
of earshot of the house. He threw open the door, entered the cab, and
was about to pull the door shut after him when he felt his wrist seized
from behind in a powerful grasp, and before he realized what had
happened, Dr. Hartmann had stepped into the cab and closed the door. The
chauffeur at once started off at a great rate.

"I'm sure, Mr. Brooks," said the doctor, suavely, as he sat down in the
forward seat, his right hand still grasping Duvall's wrist, "that you
will not mind taking me home with you. It is a long walk, and I fear
there are no other taxicabs in sight."

Duvall looked at him sternly, then attempted to draw away his hand.
"What do you mean, monsieur," he asked, harshly, "by detaining me in
this manner?" He again tried to free his wrist, but the doctor was too
strong for him.

Hartmann smiled pleasantly. "I feared, Mr. Brooks," he said, "that you
might be tempted to use the revolver which you have in the pocket of
your coat." He reached over quickly with his other hand and drew the
revolver from the detective's pocket.

Grace, through all this, had said absolutely nothing. She realized how
fatal any interruption by herself might be. She did not know of her
husband's intention to leave Brussels that night. She had heard him
order the chauffeur to drive to the sanatorium. Perhaps he wished her to
return there. In that event, it was imper