Matt and Dick, when they left their Dutch chum and the girl, hurried to police headquarters.
When the chief saw Matt, he threw up his hands.
"Did your air ship give out on you?" he asked. "I thought you were well on your way to New York by this time."
What Matt had to say about the air ship nearly took the chief's breath. Then, when he realized all that recent events meant, his temper got the better of him.
"I've got a fine force of roundsmen and detectives," said he sarcastically, "when a pack of scoundrels we're looking for can pull off a trick like that right in the outskirts of town!"
Matt eased the chief's anger somewhat by telling him of the clue they had received as to Brady's whereabouts, and he explained how he and his friends were going to get Jerrold's air ship and follow the clue across the lake.
"Now that sounds mighty good," said the chief, a flicker of hope crossing his face, "and of course the South Chicago police department ought to be represented in the expedition. Suppose I send Harris, in plain clothes, along with you? He knows St. Jo, Benton Harbor, Grand Haven, and all those places across the lake like a native. He'll be a help. Unless I'm mightily mistaken, this man Ochiltree is an old-time crook, and has served a term or two in the 'pen.' Anyhow, his name is familiar to me. But you boys are in a hurry and I won't detain you. Go on to Jerrold's. I'll have Harris get into civilian's clothes and join you there."
Fifteen minutes later, Matt and Dick were at the inventor's rambling old house. Hamilton Jerrold himself answered Matt's ring, caught him by the hand with the utmost cordiality, and ushered him and Ferral into the sitting room.
"It does my eyes good to see you again, Matt," beamed Jerrold. "You've been making some fine flights with the Hawk for the police department. Jupiter, but you're a wonder when it comes to handling anything that's driven with an explosive engine."
Matt flushed and made a deprecatory gesture.