“I think so, too.”

“I’m sure your wife will excuse us.”

She bowed and smiled agreeably, and Nick and Patsy followed Mantell into the library, a superbly furnished room overlooking the side grounds.

“Now, Nick, what can I tell you?” he asked, placing chairs for them. “Why have you come here?”

“To begin with, Mantell, I want to see the letter written to you by Calvin Vandyke,” said Nick. “Where have you kept it?”

“Here, in my desk,” said Mantell, rising to unlock a large roll-top desk in one corner of the spacious room.

“Is your desk usually locked?”

“Always, Nick, when I am absent.”

“Wait one moment,” said the detective. “Let me examine the lock.”

Mantell complied, handing him the key.