Tom got a letter one day—a letter in a strange hand, the stamp and postmark showing that it had come from the land of the Czar.
"What do you suppose it contains?" asked Ned, who was with his chum when the communication was received.
"Haven't the least idea; but I'll soon find out."
"Maybe it's from the Russian police, telling you to keep away from Siberia."
"Maybe," answered Tom absently, for he was reading the missive. "I say!" he suddenly cried. "This is great! A clew at last, and from St. Petersburg! Listen to this, Ned!
"This letter is from the head of one of the secret societies over there, a society that works against the government. It says that Mr. Petrofsky is being detained a prisoner in a lonely hut on the Atlantic sea coast, not far from New York—Sandy Hook the letter says—and here are the very directions how to get there!"
"No!" cried Ned, in disbelief. "How in the world could anybody in Russia know that."
"It tells here," said Tom. "It's all explained. As soon as the secret police got Mr. Petrofsky they communicated with the head officials in St. Petersburg. You know nearly everyone is a spy over there, and the letter says that Mr. Petrosky's
