There was a letter for Stuart at the Inn. He looked at the envelope, and decided it must be from Harry Vincent.
Stuart had been expecting such a letter. Harry had instructed him to watch for one, and to be sure that no one saw him read it, for it might contain important instructions.
Opening the letter in a corner of the lobby, Stuart eagerly devoured its contents. It contained both information and orders; one as surprising as the other.
There will be danger at Greenhurst, soon. Stay with Sherwood Mayo constantly. The old man who works with Grady is named Jeremiah Benson. Inform me immediately if you hear any reference to that name. If Mayo leaves Greenhurst, try to accompany him. Be near a radio at either six o'clock or nine o'clock. The announcement from WNX will have a message for you. Listen for any words that are emphasized. They will be the message.
This is a test for future use.
Stuart reread the letter. It was clear on every point, but he wanted to be sure that he understood all its contents well enough to remember the data, for he intended to destroy the note immediately. Looking across the lobby, he repeated certain facts; "Jeremiah Benson — stay with Mayo — WNX at six or nine — "
Nodding, Stuart again glanced at the letter. His eyes stared in bewilderment. While he had been looking away, the writing had completely disappeared!
Stuart turned the paper over, and found the other side blank. He crumpled the sheet and tossed it in the wastebasket.
"Clever idea," thought Stuart, as he entered the dining room.
It was after six o'clock when he had reached the hotel. He would have to wait for the nine-o'clock broadcast. He could hear it at Mayo's. Stuart had been out all afternoon; otherwise he would have received the letter a few hours before.