“A trap?” Tom’s brow wrinkled.

“Sure. We’ll get their picture. You see,” he explained eagerly, “I’ve placed flash bulbs attached to flash lights close to the door. By a switch and wires outside I can set them off without being seen. At the same time I can open the shutter to a camera hidden behind a picture.”

“Keen!” said Tom. “Only you can’t pull off your stunt until the zero hour. Don’t shoot too soon or you’ll scare them away.”

“I’ll wait ’till I see the whites of their eyes,” said Jimmie. “One thing more,” he added, “We found one of those gold nuggets.”

“Whe—where is it?” Tom demanded.

“John Nightingale has it.”

“That’s great!” said Tom. “I’ll get it. Then I’ll take it to that owner of the gold mine. He’ll have samples of his placer gold. We’ll have some of it and this nugget tested. See if they’re the same gold. If it is we’ve got a case against Stumps.”

“And you’ll arrest him?” said Jimmie.

“No—o. Not yet,” Tom drawled. “We’ve got a strong, broad net out. We’ll gather the whole bunch in at once. You see, if we don’t——”

To Jimmie the workings of a city detective was a matter of great mystery. They might have a clear case on a man but would not take him in. How strange!