“But you mustn’t run into danger!” stipulated Ruth. “You and Agnes and Neale are all rash.”

“No, that would be foolish,” said Mr. Howbridge with a quick, discerning glance at the two young people. He understood how matters were going between his ward and the young collegian.

“Oh, we’ll be careful,” promised Luke.

“Well, of course, being a lawyer, I suppose I ought to advise you to call in the authorities,” said the girls’ guardian. “But as there is nothing yet to interest the public, I don’t see why you can’t carry on your private investigations a bit longer, if you like.”

“Thank you. We will.”

“Only, as Ruth says, don’t run into danger,” went on Mr. Howbridge. “You, Luke, have had one example of how desperate these men are—provided the one who struck you down is one of the same pair that first was seen around the Corner House. They will not stop at injuring those who get in their way. So be careful!”

“I will, yes, and I’ll warn the others. And now to solve the mystery of the Corner House!” he cried, more gaily than he felt, for his head was still painful.

Returning to the old mansion, Ruth and Luke found there had been no new developments since they had left to see the lawyer. Neale and Hal and Agnes had “prospected” around the cellar, as they called it, but had discovered nothing.

An investigation of the doorbell wires and battery disclosed, however, the reason for the erratic behavior of that piece of apparatus. There was a loose wire, and when the house was jarred, as by a thunderclap, the wire made a connection and started the bell to ringing.

“So the men in the cellar had nothing to do with that,” declared Neale, when he had found and remedied the trouble.