Tommy flushed.
“If you think, Inspector—” he began heatedly.
But the Inspector raised a soothing hand.
“I’ll tell you what I think, Mr. Blunt. The place you want to be at eleven o’clock tonight is here in this office.”
“What?” cried Tuppence, astonished.
“Here in this office. Never mind how I know—departments overlap sometimes—but you got one of those famous ‘Blue’ letters today. Old what’s his name is after that. He lures you up to Hampstead, makes quite sure of your being out of the way, and steps in here at night when all the building is empty and quiet to have a good search round at his leisure.”
“But why should he think the letter would be here? He’d know I should have it on me or else have passed it on.”
“Begging your pardon, sir, that’s just what he wouldn’t know. He may have tumbled to the fact that you’re not the original Mr. Blunt, but he probably thinks that you’re a bona fide gentleman who’s bought the business. In that case, the letter would be all in the way of regular business and would be filed as such.”
“I see,” said Tuppence.
“And that’s just what we’ve got to let him think. We’ll catch him red handed here tonight.”
“So that’s the plan, is it?”
“Yes. It’s the chance of a lifetime. Now, let me see, what’s the time? Six o’clock. What time do you usually leave here, sir?”
“About six.”