I think people enjoy a series. When you like a story, many readers want more of the same, which is dandy, if the author and the characters have more to say.

Now, of course, the great thing about the solar system as a frontier is that there are no Indians, so you can have all the glory of the myth of the American westward expansion without any of the guilt.

My joking answer to this question is that I leave a bowl of milk out on the back porch every night for the Idea Fairy. In the morning, the milk is gone and there's a brand-new shiny idea by the bowl.

Fortunately, many people also enjoy a stand-alone as a sample of something new, like trying the special at a favourite restaurant one night instead of going for the usual.

First and foremost, The Quiet Invasion is a first contact story. What would we do if we actually found evidence of alien life out there? It's also about politics.

I did not feel I could create a more beautiful or interesting Mars than Kim Stanley Robinson or Greg Bear had, so I turned my attention elsewhere.

Octavia Butler, of course, is brilliant and disturbing.