the disappearance of the young lady. They were aware that they
had to deal with a criminal of great ability who would be careful
not to fall into the usual slips made by his kind.

There was no news from the cab either, although several detectives
were out looking for it. It was almost nightfall when Amster ran
breathlessly into room number seven. "I have him! he's waiting
outside across the way!" This was Amster's report.

Muller threw on his coat hastily. "You didn't pay him, did you?
On a cold day like this the drivers don't like to wait long in any
one place."

"No danger. I haven't money enough for that," replied Amster with
a sad smile. Muller did not hear him as he was already outside.
But the commissioner with whom he had been talking and to whom
Muller had already spoken of his voluntary assistant, entered into
a conversation with Amster, and said to him finally: "I will take
it upon myself to guarantee your future, if you are ready to enter
the secret service under Muller's orders. If you wish to do this
you can stay right on now, for I think we will need you in this case."

Amster bowed in agreement. His life had been troubled, his
reputation darkened by no fault of his own, and the work he was
doing now had awakened, an interest and an ability that he did not
know he possessed. He was more than glad to accept the offer made
by the official.

Muller was already across the street and had laid his hand upon the
door of the cab when the driver turned to him and said crossly,