A respectable Manchester solicitor received four anonymous letters demanding payment.

Each contained a single sentence:

"Tell no one, or the fifth letter will be addressed to your wife."

The solicitor paid.

A month later, the letters began again.

This time Cryer became involved.

The envelopes were ordinary, but the paper was unusual: thick cream stock carrying tiny flecks of blue fibre.

Cryer traced the paper to a particular stationery supplier.

Only one local business had purchased it in quantity.

A printer.

Cryer visited the premises and found a young clerk named Arthur Vane working late.

Vane admitted writing the letters.

But he was not the blackmailer.

He had been paid to deliver them.

The real culprit was the solicitor's business partner, who had discovered evidence of fraudulent accounts and intended to use the letters to force the solicitor into silence.

Cryer recovered the account books.

The partner was arrested.

The final letter was never sent.

It was found folded inside the blackmailer's desk.

Its contents were addressed not to the solicitor, but to Detective Sergeant Cryer.