He glanced at Wrentham as he spoke, and that gentleman assumed an air of curiosity and interest.

‘Begin with Tuppit at once: that will cut the thing short,’ said Shield, as if already impatient of the delay caused by these preliminaries.

‘Then here is a sheet of paper which Mr Shield has already signed,’ said Mr Beecham. ‘Will you put down your name, Mr Philip, and you, Mr Wrentham?’

They signed at once, and there was no reluctance apparent on the part of either, but the grand flourish which Wrentham was in the habit of drawing under his signature was not quite so steady as usual.

‘Now,’ proceeded Mr Beecham, ‘here is a scrap of paper on which Mr Shield has written a few words. Will you both write something on separate slips, and that will enable us to test Mr Tuppit’s skill in distinguishing the writers.’

This having been done, the sheet bearing the three signatures was first given to Tuppit, and it shook slightly in his hand as he advanced to the window to inspect it carefully. He then laid the paper on the table.

‘I think I know the character of the writings now,’ he said.

The three slips were next handed to him, and he named the writer of each correctly.

‘Clever chap—knows what he is about,’ was Shield’s comment. Then looking almost fiercely at Coutts: ‘Suppose you have brought your paper with you?’

‘Certainly.’