"Alone?"
Rabaul nodded.
"Um. Has he ever received messages from the Cloud Mountains? Radio calls?"
"Yes," admitted Rabaul grudgingly. "Though I can't tell you what they're about. I've instructions to call him immediately when the call signals come through. He takes them personally."
"Have you ever known him to make trips into the mountains?"
Again the Martian nodded. "Yes. He's made expeditions into them after botanical specimens, I believe."
"We got him!" said the Commissioner and Cosmo could see him counting his half of the reward. "That map is the most damning evidence of all. It's in his handwriting, isn't it?"
"You can have it checked," said Cosmo complacently. "But there's one thing more."
"Eh?"
"Motive."