Adam Gopnik

'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.

'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.