The detective gave an exclamation of surprise.

"Why are you astonished at this?" asked Fellner.

"According to her notebook, the young lady does not seem to know of this
step-brother."

"She does not know, sir. There was an ugly scandal in her family before
her birth. Her father turned his first wife and their son out of his
house on one and the same day. He had discovered that she was deceiving
him, and also that her son, who was studying medicine at the time, had
stolen money from his safe. What he had discovered about his wife made
Langen doubt whether the boy was his son at all. There was a terrible
scene, and the two disappeared from their home forever. The woman died
soon after. The young man went to Australia. He has never been heard of
since and has probably come to no good."

"Might he not possibly be here in Europe again, watching for an
opportunity to make a fortune?"

Fellner's hand grasped that of his visitor. The eyes of the two men
gazed steadily at each other. The old man's glance was full of sudden
helpless horror, the detective's eyes shone brilliantly. Muller spoke
calmly: "This is one clue. Is there no one else who could have an
interest in the young lady's death?"

"No one but Egon Langen, if he bear this name by right, and if he is
still alive."

"How old would he be now?"

"He must be nearly forty. It was many years before Langen married
again."

"Do you know him personally?"

"Have you a picture of Miss Langen?"

Fellner rang a bell and Berner appeared. "Give this gentleman Miss
Asta's picture. Take the one in the silver frame on my desk;" the old
gentleman's voice was friendly but faint with fatigue. His old servant
looked at him in deep anxiety. Fellner smiled weakly and nodded to the
man. "Sad news, Berner! Sad news and bad news. Our poor Asta is being
held a prisoner by some unknown villain who threatens her with death."

"My God, is it possible? Can't we help the poor young lady?"

"We will try to help her, or if it is--too late, we will at least avenge
her. My entire fortune shall be given up for it. But bring her picture
now."

Berner brought the picture of a very pretty girl with a bright
intelligent face. Muller took the picture out of the frame and put it in
his pocket.

"You will come again? soon? And remember, I will give ten thousand
guldens to the man who saves Asta, or avenges her. Tell the police to
spare no expense--I will go to headquarters myself to-morro