‘Works on them? What do you mean?’
‘Penny Blacks are valued according to the plates they were printed from, sir. There are distinctive markings on each of the plates, most particularly in the shape of the guide letters that appear in the corners. The stamps Messiter has been selling are doctored to make them appear rare. He buys a common Plate Six stamp in London, touches up the guide letters and sells it to a Manchester dealer as a Plate Eleven stamp for a hundred pounds. As it’s catalogued at twice that, the dealer thinks he has a bargain. Messiter picks his victims carefully: generally they aren’t specialists in early English stamps, but almost any dealer is ready to look at a Penny Black in case it’s a rare one.’
Braid shook his head. ‘I don’t understand this at all. Why should Messiter have needed to resort to forgery? There are twenty thousand stamps upstairs.’
‘Have you seen them?’
‘No, but the newspaper announcement—’
‘That fools everyone, sir.’
‘You said it was genuine.’
‘It is. And the idea of a roomful of Penny Blacks excites people’s imagination. They want to believe it. That’s the secret of all the best confidence tricks. Now why do you suppose Messiter had a mortice lock fitted on that room? You thought it was because the contents were worth a fortune? Has it occurred to you as a possibility that he didn’t want anyone to know there was nothing there?’
Braid’s dream disintegrated.
‘It stands to reason, doesn’t it,’ the inspector went on, ‘that the stamps were stripped off the wall generations ago? When Messiter found empty walls, he couldn’t abandon the idea. It had taken a grip on him. That young woman who thought of papering her wall with stamps could never have supposed she would be responsible over a century later for turning a man to crime.’ He held out his hand. ‘If I could have that key, sir, I’d like to see the room for myself.’
Braid followed the inspector upstairs and watched him unlock the door. They entered the room.
‘I don’t mind admitting I have a sneaking respect for Messiter,’ the inspector said. ‘Imagine the poor beggar coming in here at last after going to all the trouble he did to find the place. Look, you can see where he peeled back the wallpaper layer by layer’ — gripping a furl of paper, he drew it casually aside — ‘to find absolutely—’ He stopped. ‘My God!’
The stamps were there, neatly pasted in rows.
Braid said nothing, but the blood slowly drained from his face.
Miss E.D.’s scheme of interior decoration had been more ambitious than anyone expected. She had diligently blocked out each stamp in ink — red, blue or green — to form an intricate mosaic. Penny Blacks or Twopence Blues, Plate Six or Plate Eleven, they were as she had described them in The Times, worthless little articles.