How long have they been on Mars?
Why are they watching Earth? (Is the purple planet their homeworld?)
How did they learn written English ? (and why do they write backwards?)
Why did they expect the probes to be able to communicate in English?
(Did they teach Daniel "rock talk"? Can they reassemble Daniel too and maybe include the drone's transmitter so that he can speak like the other probes?)
How do they "work"?
How many are on Mars? (Were there any other places that brothers explored? -- Other survivors maybe?)
What are their capabilities? (Can they reopen the Groove? How does the Groove work, anyway?)
What is the extent and function of the rest of their tunnel facility? (Can the probes use it as a refuge when P&H's probes show up?)
joule