The detective smiled blandly in the comfortable knowledge of his own superior wisdom.
"The thieves were only frightened off that time," said he; "they will come again, feeling secure in the belief that the girl played the ghost to perfection. The next time do not be frightened but make an instant effort to capture her, and she can soon be forced to reveal her accomplices."
"You have learned nothing yet about the grave-robbers?" asked Mr. Lawrence, dismissing the first subject, thinking it quite possible that Mr. Shelton's exposition of the case was a very correct one.
"I have found the first link in the chain," said the detective brightening up.
"You have?" said the banker, gladly.
"It is a very slight clew, though," said Mr. Shelton. "I would not have you build your hopes on it, Mr. Lawrence, for it may not lead to anything. The case is a very mysterious one, and so far has completely baffled thorough investigation."
"But that you have discovered anything at all is an earnest of hope," said the banker. "Slight things lead to great discoveries sometimes. Will you give us the benefit of your discovery?"
"It must be held in the strictest confidence," said Mr. Shelton, looking from Mr. Lawrence to Mr. Darling, who had sat quite silent throughout the interview. "Of course you know that if suffered to get abroad it would put the guilty party on their guard."
Both gentlemen promised that they would preserve inviolable secrecy.
"Briefly, then, I have learned that the sexton was bribed to lend out the key of your vault the night of the funeral, Mr. Lawrence."