"What's the matter?" asked Frank.
"Little boys should be seen and not heard," grunted Aunt Gertrude, glaring at him over the tops of her spectacles.
"I sent a telegram to your father, telling him about the letter," their mother explained. "I think he should know about it. And, besides, I've been worrying because he hasn't written."
"Where did you address the telegram?"
"He gave me two addresses where I would be sure to find him in Chicago," said Mrs. Hardy. "He gave me the name of the hotel he would be staying at and he also said that Police Headquarters would reach him. I sent the same telegram to each place so I'd be sure to get him."
"Waste of money," sniffed Aunt Gertrude.
At that moment the telephone rang. Mrs. Hardy answered it. The 'phone was in the hallway and the boys could not hear their mother's words, but when she returned to the room a few minutes later they saw that she was pale with apprehension.
"The telegraph company tells me that there is no Fenton Hardy registered at the hotel and that Police Headquarters say he hasn't shown up there either," she announced gravely.
The boys looked at each other in surprise.
"That's strange," said Frank. "And he
