Mr. Nichols entered the office just as Penny hung up the phone.
"Anything wrong?" he asked quickly, noticing the expression on her face.
"Well, it looks as if I'm on the right trail," Mr. Nichols declared, not in the least disturbed. "I'd have preferred that the Molberg gang hadn't learned I was shadowing them, but such news travels fast through underground channels."
"I'm afraid some of those dreadful men may harm you," Penny said anxiously. "Promise me you'll be careful."
"I am always careful, my dear, but I refuse to go around wearing a bullet proof vest. This isn't the first warning telephone call I've received."
"I suppose not," Penny sighed. "But I should think that if the members of the Molberg gang know you have been assigned to the case, it would be hard to secure evidence against them."
"It won't be easy," the detective agreed. "However, I flatter myself that I have a few trained investigators whose activities will never be suspected."
"You mean they mingle with underworld characters and try to gain their confidence?"
"Yes, that's the usual plan. When I locate Rap Molberg I'll have him constantly shadowed."
"I've never seen many of your assistants around the office," Penny remarked.
"Naturally not," Mr. Nichols smiled. "If they came here to report, every crook in Belton City would be aware of it within an hour."
"Then how do you keep in touch with your men?" Penny asked curiously.
"There are a few secrets which I must keep to myself. Aren't you taking a rather sudden interest in my work, Penny?"
"Perhaps I am. Since my car wheels were stolen I feel personally concerned in the case. I wish I could do something to help."
Mr. Nichols became grave. "There is nothing you can do, Penny. The last thing in the world that I could wish would be to have you involved in the case. In fact I've been worried for fear----"
"For fear of what?" Penny demanded as her father checked himself.
"I've been afraid that the Molberg gang might attempt to strike at me through you. Until this case is finished you must be very careful."
"I'll be careful, although even for you I refuse to go around wearing a bullet proof vest," Penny grinned, paraphrasing his previous words. "Anyway, it might be exciting to be kidnapped."
