“You must have something on you, some evidence of identity,” said the blond man patiently. “Please.”

He did not openly suggest that if none were produced, the matter could be continued at headquarters. That would have been superfluous.

Simon produced his wallet, and watched interestedly while Zuilen glanced at the contents. The detective’s eyes snapped from the first card that caught them to the Saint’s face as if a switch had been flicked, but his manner remained painstakingly correct.

“Mr Templar,” he said, “I did not hear that you were a writer.”

“It’s a new racket,” said the Saint easily.

The blond man handed the wallet back.

“You would do well to search for your material somewhere else,” he said. “There is nothing to interest you here.”

“Now wait a minute,” Simon argued. “I’m not making any trouble. I was told on the best authority that Mr Jonkheer had received a diamond called the Angel’s Eye to re-cut. I simply asked him about it. That isn’t a crime.”

“I am glad there is no crime,” said the burly man stolidly. “We do not like to have crime from foreigners, especially during the tourist season. Mr Jonkheer does not have any such diamond. Also he does not wish to be bothered. It is better that you do not make any trouble.” He held the door firmly open. “Good day, Mr Templar.”

A few moments later, without a harsh word having been spoken or an overt threat having been uttered, the Saint found himself indisputably out on the sidewalk, blinking at the noonday sunshine and listening to the rattle of chain and bolts being refastened on the inside of the old oak door.