ps, while Harrigan came behind.

The cab rumbled away.

Cavendale pressed the push-button of the electric doorbell in a peculiar
manner. After a time there sounded from the inner side of the door an
odd knocking. Cavendale answered in a similar manner.

There was a sound of shooting bolts, but the rattle of a chain followed,
and the door was opened only a short distance. Plainly the chain was
still on.

Cavendale whispered to some one within. The door closed again, the chain
rattled once more, the door re-opened, and into the house of mystery
they walked.

The hand of Cavendale guided Dade through the dark hall, through a room
beyond and finally into still another room, which was dimly lighted.

"Here we are," said Cavendale, with affected cheerfulness. "Let's have
these lights up. The chief was abed, but he'll be down directly."

The lights were turned up. The room was plainly furnished, and had but
one window. That window was so heavily curtained that no gleam of light
could be seen from it by any one on the outside.

Hagan pretended to joke and talk in a lively manner, but his jokes were
forced and mirthless.

After a few minutes a soft step sounded outside, and a striking-looking
man in black entered the room. This man was slender and graceful, his
figure being that of a young man, but his face was one that proclaimed
him nearing seventy, and his hair was white as driven snow. One glance
at his eyes was enough for Dade, who knew instantly that they were the
same eyes he had seen peering through the transom of the Bowery hotel.

This was Frank Merriwell's deadly enemy, a monster who would hesitate at
no crime in order to injure the youth he so bitterly hated. This was the
man who had twice attempted to destroy the life of Inza Burrage. This
was the man who had poisoned Watson Scott at the Waldorf and had nearly
brought about the death of Warren Hatch in an automobile smash-up.

Morgan had good nerves. He managed to keep his face impassive as he was
introduced by Hagan, who said:

"Mr. Brown, this is Mr. Morgan, a young man who is willing to join us
and work with us when he is satisfied that the business is legitimate
and the reward sufficient."

"I am very glad to know you, Mr. Morgan," said "Brown," clasping Dade's
hand and looking into his eyes.

The voice was low and musical, but Morgan felt a thrill at the touch of
that hand, and in the steady, piercing glance of those eyes there was
something th