"You can release him now," he said to the big Austrian's captor. "He'll make no break while I have him covered. He knows me too well by this time, don't you, Robard?"
The latter's reply was a low growl.
The other Austrian released his hold, and stood back. For an instant it seemed that Robard would spring forward and give battle to all three, but as Chester's revolver covered him steadily, he changed his mind and stood still.
Immediately the others began the work of reviving the ambassador, and five minutes later their efforts were rewarded. The ambassador moaned feebly, and a few seconds later sat up. His eyes fell on Robard, and he jumped quickly to his feet.
"So!" he exclaimed. "Guard him carefully, boy. He's a dangerous man."
"I'll guard him," replied Chester briefly.
Suddenly the Austrian smote himself on the breast.
"The plot!" he cried. "Robard's plot!"
"Has failed," interrupted Chester. Then noticing the look of surprise on the ambassador's face, he explained.
"We overheard the conversation in the room where we were locked, sir. My friends managed to escape and give the warning. The plot has failed. Robard told me as much."