He was mildly interested in the news about Stay, for the man had been a disappointment.

This criminal, whose love for Thornton Lyne had, as Tarling suspected rightly, been responsible for his mental collapse, might have supplied a great deal of information as to the events which led up to the day of the murder, and his dramatic breakdown had removed a witness who might have offered material assistance to the police.
Tarling closed the door of his sitting-room behind him, pulled the wallet from his pocket and laid it on the table.

He tried first with his own keys to unfasten the flap but the locks defied him.

The heaviness of the wallet surprised and piqued him, but he was soon to find an explanation for its extraordinary weight.

He opened his pocket-knife and began to cut away the leather about the locks, and uttered an exclamation.
So that was the reason for the heaviness of the pouch--it was only leather-covered! Beneath this cover was a lining of fine steel mail.