We've always assumed that if intelligent life did or does exist on Mars, they either were or are way more advanced than us and either died out before we even got started or are still there, cleverly masking themselves from us, sabotaging our attempts to explore their planet, and biding their time until we're ripe for a takeover (okay, so maybe nobody but sf writers and paranoiacs [like there's a difference?] assume that last part).

But what if we've got it all wrong? What if intelligent life does exist on the red planet, but they're some kind of primitive, underground-dwelling society, and they're scared witless by the probes and cambots and land rovers we keep sending up there? What if WE are the impending alien invasion, preparing to once again steal a bunch of land from a less advanced civilization?

... and the cogs in Jean's brain spin round and round ...