Alejandro Gonzalez Inarritu

I've never had much interest in spinoffery - the idea of writing in someone else's universe generally leaves me cold - but 'Doctor Who' is different. I've grown up with it. It's been part of my life since I was tiny, watching Jon Pertwee on a grainy black and white television in Cornwall and being terrified out of my mind.

'Star Wars,' 'Doctor Who,' 'Forgotten Realms,' even 'Firefly' and 'The X-Files' have shared world novels and other media. I can't help but notice these settings have large shelf space in bookstores, so their publishers and authors are getting something right.