"You mean the letter which Spillsbury wrote to the woman Marsh? How did that come, by the way?"
"It reached Scotland Yard by post."
"Do you know who sent it?"
"There was no covering note at all," replied Stafford. "It was in a plain envelope with a typewritten address and was sent to me personally. The letter, of course, was valueless by itself."
"Have you made any search to discover the documents which Hanson spoke about?"
"We have searched everywhere," said the other a little wearily, "but it is a pretty hopeless business looking through London for a handful of documents. Anyway, friend Boundary is free."
The other was watching him closely.
"It is a bitter disappointment to you, my young friend," he said; "you've been working on the case for years. I fear you'll never have another such chance of putting Boundary in the dock. He's got a lot of public sympathy, too. Your thorough-paced rascal who escapes from the hands of the police has always a large following amongst the public, and I doubt whether the Home Secretary will sanction any further proceedings, unless we have most convincing proof. What's this?"
Stafford had laid a letter on the table.